SIRT1/FOXO Signaling Pathway in Breast Cancer Progression and Metastasis.

Breast cancer is the second most common cancer in women. The roles of the SIRT and FoxO proteins in tumor progression are known, but their roles in metastasis have not yet been clearly elucidated. In our study, we investigated the roles of SIRT and FoxO proteins their downstream pathways, proteins p21 and p53, in tumor progression and metastasis. We evaluated these proteins in vitro using metastatic 4TLM and 67NR cell lines, as well as their expression levels in tumor-bearing mice. In addition, the regulatory role of SIRT and FoxO proteins in different transduction cascades was examined by IPA core analysis, and clinicopathological evidence was investigated in the TCGA database. In primary tumors, the expression levels of SIRT1, p21, p53, E2F1 and FoxO proteins were higher in 67NR groups. In metastatic tissues, the expression levels of SIRT1, E2F1 and FoxO proteins were found to be enhanced, whereas the levels of p53 and p21 expression were noted to be reduced. IPA analysis also provided empirical evidence of the mechanistic involvement of SIRT and FoxO proteins in tumor progression and metastasis. In conclusion, SIRT1 was found to co-operate with FoxO proteins and to play a critical role in metastasis. Additional research is required to determine why overexpression of SIRT1 in metastatic tissues has oncogenic effects.

Altered expression of Notch signaling, Tlr receptors, and surfactant protein expression after prostaglandin inhibition may be associated with the delayed labor in LPS-induced mice.

PURPOSE: This study aims to investigate whether indomethacin (IND) delays preterm birth by regulating the Notch pathway, Tlr receptors, and Sp-A in the placenta in lipopolysaccharide (LPS)-induced preterm labor (PTL) model. METHODS: CD-1 mice were distributed to the pregnant control (PC), Sham, PBS, IND (2 mg/kg; i.p.), LPS (25 µg/100 µl; intrauterine), and LPS + IND groups. The injections were performed on day 14.5 of pregnancy. Placentae were collected on day 15.5 of pregnancy, and immunohistochemical analyzes were performed. Differences in staining intensities between the Cox-1, Notch-1 (N1), Dll-1, Jagged-2 (Jag-2), Tlr-2, and Tlr-4 proteins were compared. RESULTS: Preterm labor rates were 100% and 66% (preterm delivery delayed 5 h) in the LPS and LPS + IND groups, respectively. In LPS-treated mice, a general morphological deterioration was observed in the placenta. Total placental mid-sagittal measurement was significantly reduced in the LPS-treated group, while it was similar to the PC group in the LPS + IND group. Cox-1 expression in the LZ increased, and Sp-A expression decreased after LPS injection, and IND administration diminished this increase. N1 expression increased in the labyrinth zone (LZ) and the junctional zone (JZ). Dll-1 and Jag-2 expression increased in the JZ after LPS injection (p < 0.0001). IND administration diminished Tlr-2 expression in the LZ and Tlr-4 expression in the JZ after LPS injection. CONCLUSION: In conclusion, PG (prostaglandin) inhibition may alter Notch signaling, Tlr, and Sp-A protein expression and may be associated with delayed labor in LPS-induced mice.

Relationship of Notch Signal, Surfactant Protein A, and Indomethacin in Cervix During Preterm Birth: Mast Cell and Jagged-2 May Be Key in Understanding Infection-mediated Preterm Birth.

Although it is thought that there is a close relationship between Notch signal and preterm birth, the functioning of this mechanism in the cervix is unknown. The efficacy of surfactants and prostaglandin inhibitors in preterm labor is also still unclear. In this study, 48 female CD-1 mice were distributed to pregnant control (PC), Sham, PBS, indomethacin (2 mg/kg; intraperitoneally), lipopolysaccharides (LPS) (25 µg/100 µl; intrauterine), LPS + IND, and Surfactant Protein A Block (SP-A Block: SP-A B; the anti-SP-A antibody was applied 20 µg/100µl; intrauterine) groups. Tissues were examined by immunohistochemistry, immunofluorescence, and Western blot analysis. LPS administration increased the expression of N1 Dll-1 and Jagged-2 (Jag-2). Although Toll-like receptor (Tlr)-2 significantly increased in the LPS-treated and SP-A-blocked groups, Tlr-4 significantly increased only in the LPS-exposed groups. It was observed that Jag-2 is specifically expressed by mast cells. Overall, this experimental model shows that some protein responses increase throughout the uterus, starting at a specific point on the cervix epithelium. Surfactant Protein A, which we observed to be significantly reduced by LPS, may be associated with the regulation of the epithelial response, especially during preterm delivery due to infection. On the contrary, prostaglandin inhibitors can be considered an option to delay infection-related preterm labor with their dose-dependent effects. Finally, the link between mast cells and Jag-2 could potentially be a control switch for preterm birth.

Deleterious reproductive effects of nilotinib in mouse model.

Nilotinib is a second-generation tyrosine kinase inhibitor (TKI) that is widely used to treat patients with Philadelphia chromosome-positive chronic myeloid leukaemia (CML). TKIs provided a significant improvement in terms of survival rates and disease-free period in CML; however, there is insufficient knowledge about their side effects, including reproductive toxicity. Since nearly half of the CML patients are in their reproductive age, and newly announced indications cover the treatment of the paediatric age groups, concerns arise about the effects of these drugs on the reproductive system, as there are no controlled preclinical studies. We investigated acute and long-term gonadotoxic and teratogenic effects of nilotinib, utilising a mouse model that simulates various clinical scenarios. We observed significant testicular damage in mice receiving nilotinib according to Johnsen's score analysis. Alterations were observed in female mice's number of follicles, as the primordial follicle numbers significantly decreased. Proliferating cell number in both genders' gonads decreased and apoptosis rate increased significantly. The nilotinib-received female and male mice's pregnancy rates were low compared to controls. A significant decrease in the thickness of the spongiotrophoblast and decidual layers of the placenta was detected in pregnancies consisting of male and/or female mice treated with nilotinib. The results of this study establish a critical point of view for clinical translation and indicate the importance of consulting patients for directing them to fertility preservation and contraception options for both genders before nilotinib treatment.

PFA is superior to glyoxal in preserving oocyte, embryo, and stem cell proteins evidenced by super-resolution microscopical surveys of epitopes.

PURPOSE: Chemical fixation is a critical step to retaining cellular targets as naturally as possible. Recent developments in microscopy allow sophisticated detection and measuring techniques with which spatio-temporal molecular alterations are conceivable. In this study, we compare two members of aldehyde fixatives [i.e., glyoxal (Gly) and paraformaldehyde (PFA)] to determine whether Gly, a less toxic dialdehyde fixative that is considered to retain immunoreactivity could provide a successful and consistent cell fixation in favor of PFA in various cell preparations and types. METHODS: We document the fixation competence of Gly and PFA side-by-side (with or without Triton X-100 permeabilization) in live- and fixed-cell preparations in mouse oocytes, embryos, and human somatic cells (human umbilical cord-derived mesenchymal stromal cells) using protein quantification by Western blot assay and super-resolution microscopy. RESULTS: Although Gly seemed to act faster than PFA, catastrophic consequences were found not acceptable, especially in oocytes and embryos. Due to cell lysate and immunocytochemistry surveys, it was obvious that PFA is superior to Gly in retaining cellular proteins in situ with little/no background staining. In many samples, PFA revealed more reliable and consistent results regarding the protein quantity and cellular localization corresponding to previously defined patterns in the literature. CONCLUSION: Although the use of Gly is beneficial as indicated by previous reports, we concluded that it does not meet the requirement for proper fixation, at least for the tested cell types and proteins. However, PFA alone with no addition of TX displayed a significant cytoplasmic loss by generating membrane blebs during fixation.

Correction to: FoxO transcription factors regulate mouse preimplantation embryo development.

The original article unfortunately contained a mistake. There is a misplaced "1" in the article title and the correct title is shown above.

FoxO transcription factors 1 regulate mouse preimplantation embryo development.

PURPOSE: The aim of the present study is to investigate role of FoxO transcription factors in preimplantation embryo development by knocking down FoxO1, FoxO3, and FoxO4 genes and also to assess cell cycle arrest related proteins, p53 and p21, and apoptosis-related proteins, fas ligand (FASL), and cleaved caspase 3. METHODS: Knockdown of FoxOs using siRNA was confirmed utilizing RT-PCR and qRT-PCR in gene level and using immunofluorescence in protein level. Following knockdown of FoxO1, FoxO3, and FoxO4 in two-cell mouse embryos with or without resveratrol treatment; developmental competence of embryos and expression patterns of SIRT1, p53, p21, FASL, and CLEAVED CASPASE 3 proteins in embryos by immunofluorescence were assessed after 48 h. ROS levels were measured in knockdown embryos. Terminal deoxynucleotidyl transferase dUTP nick end labeling assay was used to determine resveratrol dose. RESULTS: Successful knockdown of FoxO genes in mouse embryos utilizing a non-invasive siRNA method was achieved. Significantly, knockdown of FoxO genes impaired preimplantation embryo development which cannot be prevented by resveratrol treatment. Immunofluorescence results showed that resveratrol could protect embryos from cell cycle arrest and apoptosis. FOXO proteins regulate apoptosis and cell cycle related proteins in mouse preimplantation embryos. Moreover, there might be an autofeedback mechanism where FOXO1, FOXO3, and FOXO4 regulate SIRT1 protein expression. CONCLUSIONS: These results suggest that FOXO transcription factors could contribute to mouse preimplantation embryo development, and it remains to investigate whether they have crucial roles in human preimplantation embryo and infertility.

Doxorubicin-induced testicular damage is related to PARP-1 signaling molecules in mice.

BACKGROUND: Doxorubicin (DOX), is a chemotherapeutic agent, which evokes oxidative stress and cell apoptosis in testicular tissue. It is known that the activation of the nuclear enzyme poly (ADP-ribose) polymerase (PARP), leading to apoptosis induced by DOX. The aim of the present study is to investigate whether PARP pathway has a role in DOX-induced testicular damage and infertility utilizing pharmacological PARP-1 inhibitor, PJ34, and PARP-1 knockout mice model. METHODS: Firstly, we assessed the activation of PARP pathway after DOX-induction at various hours by immunohistochemistry and western blot analysis. Secondly, we evaluated the role of PARP pathway in DOX-induced testicular damage, sperm motility, and fertility with pharmacological inhibition of PARP by using PJ34. Finally, we aimed to correlate a functional relationship between PARP-1 and DOX using PARP-1 knockout mice in DOX-induced testicular damage. Doxorubicin levels in plasma and testis tissue were also assessed. RESULTS: In DOX-induced group; PARP-1, PAR and apoptotic pathway protein expressions, increased significantly. In DOX + PJ34 group; PAR, cytochrome c, and AIF levels decreased significantly. Testicular weights, sperm motility, and mean the number of pups per litter decreased in DOX-induced group after 28 days, however they were similar to the control group in DOX-PJ34 group. In PARP-1 KO group, seminiferous tubule morphology was impaired significantly after 28 days of DOX-administration. CONCLUSIONS: Our study indicates that DOX-induced testicular damage may be related to over-activation of PARP-1. PJ34 application was effective in preventing severe testicular damage caused by DOX-injection and may be considered for fertility protection against DOX-induced testicular damage.

Spatiotemporal expression and regulation of FoxO1 in mouse uterus during peri-implantation period.

Recent studies indicate that FoxO1 has roles in female reproductive system, especially in maternal endometrium. Although various cellular aspects and molecular pathways have been identified, the exact molecular characteristics of embryo implantation are still not completely understood. In this study, we aimed to investigate uterine expression and regulation of FoxO1 during peri-implantation period in mice. Experimental mouse models including, normal pregnancy, pseudopregnancy, artificial decidualization, and delayed implantation and activation were performed. Our results showed that FoxO1 expression was spatiotemporal in mouse endometrial tissue throughout peri-implantation period and its expression was significantly upregulated in luminal and glandular epithelium at the time of implantation. Moreover, on day 5 morning (09:00 AM) of pregnancy, expression of FoxO1 was cytoplasmic in endometrial luminal epithelial cells where embryo homing takes place. With progressing time on day 5 evening (19:00 PM) of pregnancy FoxO1 expression was nuclear in luminal epithelium at implantation site. Pseudopregnancy and artificial decidualization models indicated that FoxO1 expression was regulated by pregnancy hormones. Delayed implantation and activation model indicated that FoxO1 expression at the time of implantation is dependent upon activation status of blastocyst due to E2 induction and uterine sensitivity to implantation. In conclusion, our findings highlight a perspective for FoxO1 expression and regulation in mouse uterus during peri-implantation period indicating that its expression is regulated by implanting embryo and pregnancy hormones.

Protective effect of exendin-4 treatment on erectile dysfunction induced by chronic methylglyoxal administration in rats.

OBJECTIVE: The aim of this study was to investigate the effect of chronic exendin-4 (Ex-4) treatment on corpus cavernosum (CC) dysfunction in methylglyoxal (MGO) administered rats. METHODS: Male rats were divided into four groups as control, MGO (75 mg/kg/day in drinking water for 12 weeks), MGO + low-dose Ex-4 (0.1 µg/kg twice daily subcutaneously for 12 weeks concomitant with MGO), and MGO + high-dose Ex-4 (1 µg/kg twice daily subcutaneously for 12 weeks concomitant with MGO). Nitric oxide (NO)-mediated endothelium-dependent and neurogenic CC relaxations were evaluated by acetylcholine (ACh) and electrical field stimulation (EFS), respectively. Apoptosis was determined by TUNEL. Endothelial nitric oxide synthase (eNOS), phosphorylated eNOS (p-eNOS), NADPH oxidase subunit gp91phox (NOX2), and Rho kinase (ROCK2) expressions in CC were investigated by immunohistochemistry. Levels of the malondialdehyde (MDA) and advanced oxidation protein products (AOPP) were also measured. RESULTS: In MGO administered rats, both endothelium-dependent and neurogenic CC relaxations were significantly impaired as compared to controls. Apoptotic cell death and levels of MDA and AOPP increased significantly in MGO administered rats. eNOS and p-eNOS expressions decreased significantly in MGO group, while gp91phox expressions increased significantly. The diminished relaxation in response to ACh or EFS as well as the changes in expression of proteins in MGO groups were significantly improved by exendin-4 treatment. TUNEL-positive cells, and levels of MDA and AOPP in MGO group rats were also significantly reduced by exendin-4. CONCLUSION: Exendin-4 treatment improves NO-mediated CC relaxations in MGO administered rats probably by inhibiting NADPH oxidase.

Cardioprotective effect of nesfatin-1 against isoproterenol-induced myocardial infarction in rats: Role of the Akt/GSK-3ß pathway.

The present study was designed to evaluate the cardioprotective effects of nesfatin-1, a novel peptide with anorexigenic properties, in rats with isoproterenol (ISO)-induced myocardial infarction (MI), and to further investigate the role of Akt/GSK-3ß signaling pathway in the protective effect of nesfatin-1. To induce MI, ISO was subcutaneously injected into the rats for two consecutive days at a dosage of 85mg/kg/day. ISO-induced myocardial damage was indicated by elevated levels of cardiac specific troponin-T, enhanced myocardial expression of proinflammatory cytokines (interleukin-1ß, interleukin-6 and tumor necrosis factor-α), and increased number of cells with apoptotic and necrotic appearance in the myocardial tissue. Levels of p-Akt/Akt and p-GSK-3ß/GSK-3ß significantly decreased in heart tissue after ISO-induced MI. However, intraperitoneal administration of nesfatin-1 (10µg/kg/day) elicited a significant cardioprotective activity by lowering the levels of cardiac troponin-T and proinflammatory cytokines, indicating the protective effect of nesfatin-1 against ISO-induced MI. The biochemical findings were further confirmed by histopathological examination, which was demonstrated by reduced number of apoptotic and necrotic cells. Moreover, expressions of p-Akt/Akt and p-GSK-3ß/GSK-3ß in the myocardium of MI group rats were significantly increased by nesfatin-1 administration, suggesting that nesfatin-1, which appears to possess anti-apoptotic and anti-inflammatory properties, may confer protection against ISO-induced MI via an Akt/GSK-3ß-dependent mechanism.

Myo-Inositol Safety in Pregnancy: From Preimplantation Development to Newborn Animals.

Myo-inositol (myo-Ins) has a physiological role in mammalian gametogenesis and embryonic development and a positive clinical impact on human medically assisted reproduction. We have previously shown that mouse embryo exposure to myo-Ins through preimplantation development in vitro increases proliferation activity and blastocyst production, representing an improvement in culture conditions. We have herein investigated biochemical mechanisms elicited by myo-Ins in preimplantation embryos and evaluated myo-Ins effects on postimplantation/postnatal development. To this end naturally fertilized embryos were cultured in vitro to blastocyst in the presence or absence of myo-Ins and analyzed for activation of the PKB/Akt pathway, known to modulate proliferation/survival cellular processes. In parallel, blastocyst-stage embryos were transferred into pseudopregnant females and allowed to develop to term and until weaning. Results obtained provide evidence that myo-Ins induces cellular pathways involving Akt and show that (a) exposure of preimplantation embryos to myo-Ins increases the number of blastocysts available for uterine transfer and of delivered animals and (b) the developmental patterns of mice obtained from embryos cultured in the presence or absence of myo-Ins, up to three weeks of age, overlap. These data further identify myo-Ins as a possibly important supplement for human preimplantation embryo culture in assisted reproduction technology.

Resveratrol Prevented Lipopolysaccharide-Induced Endothelial Dysfunction in Rat Thoracic Aorta Through Increased eNOS Expression.

BACKGROUND: The cardiovascular benefits of Resveratrol (RVT) have been well established by previous experimental and clinical studies. AIMS: The goal of this study was to test the effectiveness of RVT administration on the impaired endothelial function induced by lipopolysaccharide (LPS), and to elucidate the role of endothelial nitric oxide synthase (eNOS)/Sirtuin 1 (SIRT1) pathway. STUDY DESIGN: Animal experiment. METHODS: Endotoxemia was induced by intraperitoneal injection of 10 mg/kg LPS, and the thoracic aorta was isolated six hours later. RVT was injected intraperitoneally 15 minutes before LPS administration. Six hours after LPS injection, potassium chloride (KCl), phenylephrine (Phe), acetylcholine (ACh), and sodium nitroprusside (SNP) were used to examine to vascular reactivity and endothelial function. eNOS, phospho-eNOS (p-eNOS) (Ser 1177), and SIRT1 expressions in thoracic aorta were evaluated by Western blot. RESULTS: LPS administration significantly inhibited the relaxation response induced by ACh, while the relaxation to SNP was not significantly altered. Phe- and KCl-induced contractile responses in the thoracic aorta significantly decreased in LPS-injected group. eNOS and p-eNOS expression decreased significantly in arteries obtained from LPS group rats. The impaired vasoreactivity as well as decreased expressions of eNOS, p-eNOS, and SIRT1 in vessels from LPS-injected rats were improved by RVT treatment. CONCLUSION: The endothelium-dependent vasodilatation of the thoracic aorta was significantly inhibited by LPS administration, and RVT treatment may improve vascular endothelial function. The protective effect of RVT might be associated with increased eNOS expression and activity.

FOXO1, FOXO3, AND FOXO4 are differently expressed during mouse oocyte maturation and preimplantation embryo development.

Preimplantation embryo development is affected by its environment. FoxO transcription factors are regulated by PI3K/Akt signaling pathway that essentially supports growth and development. FoxO transcription factors are at the interface of crucial cellular processes, orchestrating programs of gene expression that regulate apoptosis, cell-cycle arrest, oxidative stress resistance, DNA repair, glucose metabolism, and differentiation. In the presence of growth factors, FoxO transcription factors are localized in the cytoplasm, whereas under stress conditions they move to the nucleus and trigger transcriptional activities of their target genes. The aim of the present study is to investigate whether FoxO transcription factors are present during in vivo oocyte maturation and preimplantation embryo development. Presence and localizations of FoxO1, FoxO3 and FoxO4 proteins have been determined with immunofluorescence staining. Our results have confirmed that FoxO1, FoxO3 and FoxO4 proteins are differentially expressed in prophase I, metaphase I, metaphase II oocytes, as well as in fertilized oocyte, 2-cell embryo, 4-cell embryo, 8-cell embryo, morula, and blastocyst. FoxOs translocate to nucleus in embryos with developmental delay. Our findings indicate that FoxO transcription factors are present during both oocyte and embryo in vivo maturation and provide fundamental knowledge that FoxOs may regulate in vitro embryo development under stress conditions.

Chronic treatment with taurine ameliorates diabetes-induced dysfunction of nitric oxide-mediated neurogenic and endothelium-dependent corpus cavernosum relaxation in rats.

This study was aimed to examine the effect of chronic taurine treatment on corpus cavernosum dysfunction in diabetic rats and to investigate possible underlying mechanisms. Thirty male rats were randomized to three groups of 10 each, including control, diabetic, and taurine-treated diabetic. Diabetes was induced in rats by streptozotocin (STZ, single intraperitoneal dose of 50 mg/kg body weight). Taurine was administered orally for 12 weeks (1% w/v in drinking water) from the day on which STZ was injected. At the end of the 12th week, strips of corpus cavernosum were suspended in an organ bath system for functional studies. Nitric oxide (NO)-mediated endothelium-dependent and neurogenic corpus cavernosum relaxation were evaluated by acetylcholine (ACh, 0.1-100 µm) and electrical field stimulation (EFS, 30 V, 5 ms, 2-32 Hz), respectively. The expressions of endothelial nitric oxide synthase (eNOS), phosphorylated eNOS (p-eNOS) (Ser-1177), neuronal nitric oxide synthase (nNOS), NADPH oxidase subunit gp91(phox) , Rho A, and Rho kinase in corpus cavernosum were semi-quantitatively assessed by immunohistochemistry. Induction of diabetes resulted in significant inhibition of NO-mediated endothelium-dependent and neurogenic corpus cavernosum relaxation. Furthermore, eNOS, p-eNOS, and nNOS expressions decreased significantly in diabetic rats compared to controls, while gp91(phox) , RhoA and Rho kinase expressions increased significantly. The diminished relaxation response to ACh and EFS as well as diabetes-related changes in expressions of these proteins in corpus cavernosum of diabetic rats was significantly improved by taurine. Taurine treatment improves NO-mediated relaxations of corpus cavernosum in diabetic rats probably by inhibiting NADPH oxidase/Rho kinase pathways.