The 12 kD FK506 Binding Protein FKBP12 Is Released in the Male Reproductive Tract and Stimulates Sperm Motility

Immunological properties of gold nanoparticles

In the past decade, gold nanoparticles have attracted strong interest from the nanobiotechnological community owing to the significant progress made in robust and easy-to-make synthesis technologies, in surface functionalization, and in promising biomedical applications. These include bioimaging, gene diagnostics, analytical sensing, photothermal treatment of tumors, and targeted delivery of various biomolecular and chemical cargos. For the last-named application, gold nanoparticles should be properly fabricated to deliver the cargo into the targeted cells through effective endocytosis. In this review, we discuss recent progress in understanding the selective penetration of gold nanoparticles into immune cells. The interaction of gold nanoparticles with immune cell receptors is discussed. As distinct from other published reviews, we present a summary of the immunological properties of gold nanoparticles. This review also summarizes what is known about the application of gold nanoparticles as an antigen carrier and adjuvant in immunization for the preparation of antibodies in vivo. For each of the above topics, the basic principles, recent advances, and current challenges are discussed. Thus, this review presents a detailed analysis of data on interaction of gold nanoparticles with immune cells. Emphasis is placed on the systematization of data over production of antibodies by using gold nanoparticles and adjuvant properties of gold nanoparticles. Specifically, we start our discussion with current data on interaction of various gold nanoparticles with immune cells. The next section describes existing technologies to improve production of antibodies in vivo by using gold nanoparticles conjugated with specific ligands. Finally, we describe what is known about adjuvant properties of bare gold or functionalized nanoparticles. In the Conclusion section, we present a short summary of reported data and some challenges and perspectives.

Mammalian target of rapamycin (mTOR): a central regulator of male fertility?

Mammalian target of rapamycin (mTOR) is a central regulator of cellular metabolic phenotype and is involved in virtually all aspects of cellular function. It integrates not only nutrient and energy-sensing pathways but also actin cytoskeleton organization, in response to environmental cues including growth factors and cellular energy levels. These events are pivotal for spermatogenesis and determine the reproductive potential of males. Yet, the molecular mechanisms by which mTOR signaling acts in male reproductive system remain a matter of debate. Here, we review the current knowledge on physiological and molecular events mediated by mTOR in testis and testicular cells. In recent years, mTOR inhibition has been explored as a prime strategy to develop novel therapeutic approaches to treat cancer, cardiovascular disease, autoimmunity, and metabolic disorders. However, the physiological consequences of mTOR dysregulation and inhibition to male reproductive potential are still not fully understood. Compelling evidence suggests that mTOR is an arising regulator of male fertility and better understanding of this atypical protein kinase coordinated action in testis will provide insightful information concerning its biological significance in other tissues/organs. We also discuss why a new generation of mTOR inhibitors aiming to be used in clinical practice may also need to include an integrative view on the effects in male reproductive system.

Prenatal Exposure to DEHP Affects Spermatogenesis and Sperm DNA Methylation in a Strain-Dependent Manner

Di-(2-ethylhexyl)phtalate (DEHP) is a plasticizer with endocrine disrupting properties found ubiquitously in the environment and altering reproduction in rodents. Here we investigated the impact of prenatal exposure to DEHP on spermatogenesis and DNA sperm methylation in two distinct, selected, and sequenced mice strains. FVB/N and C57BL/6J mice were orally exposed to 300 mg/kg/day of DEHP from gestation day 9 to 19. Prenatal DEHP exposure significantly decreased spermatogenesis in C57BL/6J (fold-change = 0.6, p-value = 8.7*10^-4), but not in FVB/N (fold-change = 1, p-value = 0.9). The number of differentially methylated regions (DMRs) by DEHP-exposure across the entire genome showed increased hyper- and decreased hypo-methylation in C57BL/6J compared to FVB/N. At the promoter level, three important subsets of genes were massively affected. Promoters of vomeronasal and olfactory receptors coding genes globally followed the same trend, more pronounced in the C57BL/6J strain, of being hyper-methylated in DEHP related conditions. In contrast, a large set of micro-RNAs were hypo-methylated, with a trend more pronounced in the FVB/N strain. We additionally analyze both the presence of functional genetic variations within genes that were associated with the detected DMRs and that could be involved in spermatogenesis, and DMRs related with the DEHP exposure that affected both strains in an opposite manner. The major finding in this study indicates that prenatal exposure to DEHP can decrease spermatogenesis in a strain-dependent manner and affects sperm DNA methylation in promoters of large sets of genes putatively involved in both sperm chemotaxis and post-transcriptional regulatory mechanisms.

Low-frequency germline variants across 6p22.2-6p21.33 are associated with non-obstructive azoospermia in Han Chinese men

Genome-wide association studies (GWAS) have identified several common loci contributing to non-obstructive azoospermia (NOA). However, a substantial fraction of NOA heritability remains undefined, especially those low-frequency [defined here as having a minor allele frequency (MAF) between 0.5 and 5%] and rare (MAF below 0.5%) variants. Here, we performed a 3-stage exome-wide association study in Han Chinese men to evaluate the role of low-frequency or rare germline variants in NOA development. The discovery stage included 962 NOA cases and 1348 healthy male controls genotyped by exome chips and was followed by a 2-stage replication with an additional 2168 cases and 5248 controls. We identified three low-frequency variants located at 6p22.2 (rs2298090 in HIST1H1E encoding p.Lys152Arg: OR = 0.30, P = 2.40 × 10(-16)) and 6p21.33 (rs200847762 in FKBPL encoding p.Pro137Leu: OR = 0.11, P = 3.77 × 10(-16); rs11754464 in MSH5: OR = 1.78, P = 3.71 × 10(-7)) associated with NOA risk after Bonferroni correction. In summary, we report an instance of newly identified signals for NOA risk in genes previously undetected through GWAS on 6p22.2-6p21.33 in a Chinese population and highlight the role of low-frequency variants with a large effect in the process of spermatogenesis.

Gold nanoparticles in biomedical applications: recent advances and perspectives

Gold nanoparticles (GNPs) with controlled geometrical, optical, and surface chemical properties are the subject of intensive studies and applications in biology and medicine. To date, the ever increasing diversity of published examples has included genomics and biosensorics, immunoassays and clinical chemistry, photothermolysis of cancer cells and tumors, targeted delivery of drugs and antigens, and optical bioimaging of cells and tissues with state-of-the-art nanophotonic detection systems. This critical review is focused on the application of GNP conjugates to biomedical diagnostics and analytics, photothermal and photodynamic therapies, and delivery of target molecules. Distinct from other published reviews, we present a summary of the immunological properties of GNPs. For each of the above topics, the basic principles, recent advances, and current challenges are discussed (508 references).

Sirolimus-associated infertility: case report and literature review of possible mechanisms

The mammalian-target-of-rapamycin/mTOR-inhibitor sirolimus as a component of the immunosuppressive strategy after solid organ transplantation is effective at preventing allograft rejection. However, recent reports indicate that sirolimus is associated with altered sex hormone levels and impaired sperm quality parameters. Herein, we report on a case of sirolimus-associated infertility in a young male heart-lung transplant recipient and provide a detailed synopsis of potential mechanisms by which sirolimus may negatively influence spermatogenesis. Testicular immunohistochemistry, the course of sex hormone and sperm quality parameters of our patient support the hypothesis that mTOR might act as an important key regulator in the reproductive system. Fortunately, due to withdrawal of sirolimus as part of the maintenance, immunosuppression improved sperm quality and sex hormone parameters could be observed. Recently, these improvements even resulted in a spontaneous pregnancy of the patient's wife more than 1 year after the drug was withdrawn. In our view, oligospermia as a possible and at least partly reversible side-effect of mTOR inhibitors has to be taken into consideration, particularly, when administrated to young male patients.

Neuroprotective and antiretroviral effects of the immunophilin ligand GPI 1046

HIV infection results in a neurodegenerative disorder for which currently there is no effective therapy available. Currently, available antiretroviral therapy has no impact on the production of early regulatory HIV proteins once the virus is integrated. Of these proteins, Tat was shown to be toxic to neurons. We, thus, used an in vitro neuronal culture system to determine if immunophilin ligands could protect against Tat-induced neurotoxicity. We found that GPI 1046 had potent neuroprotective effects in this model. The compound was able to protect the neurons even though it only partially obliterated Tat-induced oxidative stress in neurons, suggesting that other mechanisms may be important in mediating its neuroprotective effect. Furthermore, GPI 1046 showed inhibition of HIV replication and Tat-mediated long terminal repeat (LTR) activation suggesting that this class of compounds may be worthy of further exploration as a potential treatment for HIV dementia.

Proteome analysis of conditioned medium from cultured adult hippocampal progenitors

It is known that proliferation and survival of neural stem/progenitor cells in vitro not only depend on exogenous factors, but also on autocrine factors secreted into the conditioned medium. It is also well known that the identification of bioactive proteins secreted into the conditioned medium poses a substantial challenge. Recently, neural stem/progenitor cells were shown to secrete a survival factor, cystatin C, into the conditioned medium. Here, we demonstrate an approach to identify other low molecular weight proteins in conditioned medium from cultured adult rat hippocampal progenitor cells. A combination of preparative two-dimensional gel electrophoresis (2-DE) and mass spectrometry was utilized in the analysis. We were able to identify a number of proteins, which include Rho-guanine nucleotide dissociation inhibitor 1, phosphatidylethanolamine binding protein (PEBP), also termed Raf-1 kinase interacting protein, polyubiquitin, immunophilin FK506 binding protein 12 (FKBP12) and cystatin C. The presence of PEBP and FKBP12 in conditioned medium was confirmed immunologically. All nestin-positive progenitor cells showed immunoreactivity for antibodies against PEBP and FKBP12. To our knowledge we are the first to use this preparative proteomic approach to search for stem cell factors in conditioned medium. The method could be used to identify novel bioactive proteins secreted by stem/progenitor cells in vitro. Identification of bioactive proteins in vitro is of potential importance for the understanding of the regulatory mechanisms of the cells in vivo.

Effect of seminal plasma on the characteristics and fertility of rabbit spermatozoa

The effects of different dilutions of seminal plasma (SP) on the qualitative characteristics of rabbit spermatozoa and on their fertilising ability were analysed. Ejaculated semen was centrifuged twice and the sperm resuspended in media with decreasing ratios of SP/Tris: (1/2; 1/5; 1/10; 1/20; 1/30; 1/100) until the complete substitution was with SP. The control constituted sperm in undiluted SP. Samples were maintained at 37 degrees C and kinetic analysis done at fixed intervals (0-6h). Also the thiobarbituric reactive substances (TBA-RS) values were determined. Rabbit sperm suspended in Tris, or with extremely low content of SP, lost motility and viability within 1-3h, while sperm suspended in SP either undiluted or diluted up to 10-fold, showed similar motility during the 6h period (from 39 to 49%). Further dilutions of SP (1/20-1/30) had no effect during the initial 2h of storage but thereafter the decline of motility was more marked (after 6h: from 0 to 17%). Kinetic parameters followed the same trend and differences were particularly marked after storage: the highest values were in samples diluted up to 1/10; a sharp decline in motility characteristics was observed at higher dilutions. The addition of SP (1/2 v/v) to immotile sperm reactivated 35.5% of cells. However, SP did not significantly affect fertility rate or litter size possible involving an interaction with the female reproductive tract. SP reduced lipid oxidation (TBA-RS) of semen only after storage. A positive correlation between final TBA-RS and cell viability indicated that peroxidation was one of the cause of rabbit sperm deterioration during conservation.