Differential Proteomic Analysis of Human Sperm: A Systematic Review to Identify Candidate Targets to Monitor Sperm Quality.

Purpose: The advent of proteomics provides new opportunities to investigate the molecular mechanisms underlying male infertility. The selection of relevant targets based on a single analysis is not always feasible, due to the growing number of proteomic studies with conflicting results. Thus, this study aimed to systematically review investigations comparing the sperm proteome of normozoospermic and infertile men to define a panel of proteins with the potential to be used to evaluate sperm quality.

Bioinformatic Approach to Unveil Key Differentially Expressed Proteins in Human Sperm After Slow and Rapid Cryopreservation.

Currently, two conventional freezing techniques are used in sperm cryopreservation: slow freezing (SF) and rapid freezing (RF). Despite the protocolar improvements, cryopreservation still induces significant alterations in spermatozoon that are poorly understood. Here, available proteomic data from human cryopreserved sperm was analyzed through bioinformatic tools to unveil key differentially expressed proteins (DEPs) that can be used as modulation targets or quality markers.

Protein Mimicry and the Design of Bioactive Cell-Penetrating Peptides: The Genesis of STOPSPERM Bioportides.

The mature spermatozoon, a highly differentiated cell equipped for the sole purpose of fertilization, lacks the protein machinery required for conventional endocytotic mechanisms. Perhaps contrary to expectation, cell-penetrating peptides (CPPs) rapidly translocate across the unique sperm plasma membrane to accrete within distinct intracellular compartments. Confocal microscopy, employing red-fluorescent CPPs and bioportides, is a convenient platform to study this membrane translocation process.

Disruption of protein phosphatase 1 complexes with the use of bioportides as a novel approach to target sperm motility.

Objective: To design protein phosphatase 1 (PP1)-disrupting peptides covalently coupled to inert cell-penetrating peptides (CPPs) as sychnologically organized bioportide constructs as a strategy to modulate sperm motility.

Design: Experimental study.

Setting: Academic research laboratory.

Investigation of spectroscopic and proteomic alterations underlying prostate carcinogenesis.

Prostate cancer (PCa) treatment remains challenging, especially in advanced stages, where the lack of sensitivity and specificity of available biomarkers makes it difficult to establish an accurate prognosis. Therefore, it is imperative to study PCa biology to identify key molecules that can improve PCa management. In this study, eight prostate tumor tissues and paired normal tissues were analyzed using two approaches-Fourier-transform infrared (FT-IR) spectroscopy for spectroscopic profiling of biomolecules and antibody microarray for signaling proteins-with the main goal of identifying metabolic and proteomic changes that enable the distinction between normal and tumor conditions.

First Insights on the Presence of the Unfolded Protein Response in Human Spermatozoa.

The unfolded protein response (UPR) is involved in protein quality control and is activated in response to several stressors. Although in testis the UPR mechanisms are well described, their presence in spermatozoa is contentious. We aimed to investigate the presence of UPR-related proteins in human sperm and the impact of oxidative stress induction in UPR activation.

mTOR Signaling Pathway Regulates Sperm Quality in Older Men.

Understanding how age affects fertility becomes increasingly relevant as couples delay childbearing toward later stages of their lives. While the influence of maternal age on fertility is well established, the impact of paternal age is poorly characterized. Thus, this study aimed to understand the molecular mechanisms responsible for age-dependent decline in spermatozoa quality.

Sulfate-based lipids: Analysis of healthy human fluids and cell extracts.

Sulfate-based lipids (SL) have been proposed as players in inflammation, immunity and infection. In spite of the many biochemical processes linked to SL, analysis on this class of lipids has only focused on specific SL sub-classes in individual fluids or cells leaving a range of additional SL in other biological samples unaccounted for. This study describes the mass spectrometry screening of SL in lipid extracts of human fluids (saliva, plasma, urine, seminal fluid) and primary human cells (RBC, neutrophils, fibroblasts and skin epidermal) using targeted precursor ion scanning (PIS) approach.

Adding biological meaning to human protein-protein interactions identified by yeast two-hybrid screenings: A guide through bioinformatics tools.

Unlabelled: "A man is known by the company he keeps" is a popular expression that perfectly fits proteins. A common approach to characterize the function of a target protein is to identify its interacting partners and thus infer its roles based on the known functions of the interactors. Protein-protein interaction networks (PPINs) have been created for several organisms, including humans, primarily as results of high-throughput screenings, such as yeast two-hybrid (Y2H).

Study on the short-term effects of increased alcohol and cigarette consumption in healthy young men's seminal quality.

Many studies have reported a negative impact of lifestyle factors on testicular function, spermatozoa parameters and pituitary-gonadal axis. However, conclusions are difficult to draw, since studies in the general population are rare. In this study we intended to address the early and late short-term impact of acute lifestyle alterations on young men's reproductive function.

Construction and analysis of a human testis/sperm-enriched interaction network: Unraveling the PPP1CC2 interactome.

Background: Phosphoprotein phosphatase 1 catalytic subunit gamma 2 (PPP1CC2), a PPP1CC tissue-specific alternative splice restricted to testicular germ cells and spermatozoa, is essential for spermatogenesis and spermatozoa motility. The key to understand PPP1CC2 regulation lies on the characterization of its interacting partners.

Methods: We construct a testis/sperm-enriched protein interaction network and analyzed the topological properties and biological context of the network.

Non-stop lab week: A real laboratory experience for life sciences postgraduate courses.

At the Portuguese universities, practical classes of life sciences are usually professor-centered 2-hour classes. This approach results in students underprepared for a real work environment in a research/clinical laboratory. To provide students with a real-life laboratory environment, the Non-Stop Lab Week (NSLW) was created in the Molecular Biomedicine master program at the University of Aveiro, Portugal.

Oxidative stress markers: Can they be used to evaluate human sperm quality?

Objective: To study the effects of an acute lifestyle change in human semen oxidative stress (OS) by applying seminal parameters and OS markers and to study the feasibility of mid-infrared spectroscopy with Fourier transform infrared spectroscopy (FT-IR) as a complementary tool to evaluate the effects of OS on human sperm samples.

Material And Methods: Sperm samples were collected from healthy male students (n=8) who voluntarily submitted themselves to acute lifestyle changes during academic festivities. The samples were obtained before and after the academic festivities and were compared by basic semen analyses and OS markers, namely with thiobarbituric acid reactive species (TBARS) and total thiol (SH) groups by spectrophotometric assays and carbonyl (CO) groups by slot blot.

Profiling signaling proteins in human spermatozoa: biomarker identification for sperm quality evaluation.

Objective: To determine the correlation between semen basic parameters and the expression and activity of signaling proteins.

Design: In vitro studies with human spermatozoa.

Setting: Academic research institute.

The power of the yeast two-hybrid system in the identification of novel drug targets: building and modulating PPP1 interactomes.

Since the description of the yeast two-hybrid (Y2H) method, it has become more and more evident that it is the most commonly used method to identify protein-protein interactions (PPIs). The improvements in the original Y2H methodology in parallel with the idea that PPIs are promising drug targets, offer an excellent opportunity to apply the principles of this molecular biology technique to the pharmaceutical field. Additionally, the theoretical developments in the networks field make PPI networks very useful frameworks that facilitate many discoveries in biomedicine.

Signalling pathways involved in oocyte growth, acquisition of competence and activation.

The oocyte's primary function is to be fertilised by a spermatozoon in order to create a viable embryo. Oocyte growth and development are initiated during embryogenesis and occur in parallel to follicular development. Factors produced by the oocyte bind to receptors on follicular cells, ensuring follicular development.

Amyloid precursor protein interaction network in human testis: sentinel proteins for male reproduction.

Background: Amyloid precursor protein (APP) is widely recognized for playing a central role in Alzheimer's disease pathogenesis. Although APP is expressed in several tissues outside the human central nervous system, the functions of APP and its family members in other tissues are still poorly understood. APP is involved in several biological functions which might be potentially important for male fertility, such as cell adhesion, cell motility, signaling, and apoptosis.

Characterisation of several ankyrin repeat protein variant 2, a phosphoprotein phosphatase 1-interacting protein, in testis and spermatozoa.

Phosphoprotein phosphatase 1 (PPP1) catalytic subunit gamma 2 (PPP1CC2), a PPP1 isoform, is largely restricted to testicular germ cells and spermatozoa. The key to understanding PPP1 regulation in male germ cells lies in the identification and characterisation of its interacting partners. This study was undertaken to determine the expression patterns of the several ankyrin repeat protein variant 2 (SARP2), a PPP1-interacting protein, in testis and spermatozoa.

TGF-β cascade regulation by PPP1 and its interactors -impact on prostate cancer development and therapy.

Protein phosphorylation is a key mechanism by which normal and cancer cells regulate their main transduction pathways. Protein kinases and phosphatases are precisely orchestrated to achieve the (de)phosphorylation of candidate proteins. Indeed, cellular health is dependent on the fine-tune of phosphorylation systems, which when deregulated lead to cancer.

Prostate cancer: the need for biomarkers and new therapeutic targets.

Prostate cancer (PCa) incidence and mortality have decreased in recent years. Nonetheless, it remains one of the most prevalent cancers in men, being a disquieting cause of men's death worldwide. Changes in many cell signaling pathways have a predominant role in the onset, development, and progression of the disease.