P-030 ACE2 receptor and its isoform short-ACE2 are expressed on human spermatozoa

STUDY QUESTION: Do human spermatozoa express angiotensin-converting enzyme 2 (ACE2) receptor? What would be its localization? SUMMARY ANSWER: Human spermatozoa express uniformly ACE2 on the sperm head and the flagellum. Moreover, the short-ACE2 isoform is concentrated on the post-acrosomal region and midpiece. WHAT IS KNOWN ALREADY: The Severe Acute Respiratory Syndrome CoronaVirus-2 (SARS-CoV-2) infection is generating important concerns regarding not only the possible consequences on the respiratory system, but also on other organs, including the reproductive system. ACE2 is considered the main point of entry for the SARS-CoV-2 within the cells through the binding with the spike protein on the virus surface. Furthermore, ACE2 is expressed in human testes cells including Leydig cells, Sertoli cells and spermatogonia. However, to date, the expression and location of ACE2 in mature human spermatozoa has not been investigated yet. STUDY DESIGN, SIZE, DURATION: This was an in vitro study for the evaluation of the expression and immune-localization of full-length ACE2 and its isoform, short-ACE2, in human spermatozoa. Thirthyfour non-immunized healthy normozoospermic volunteers were enrolled in the study. The study was conducted from May to December 2021. PARTICIPANTS/MATERIALS, SETTING, METHODS: Semen samples were collected by masturbation from non-immunized healthy normozoospermic voluntaries. Motile sperm suspensions were obtained by swim-up procedure. The expression of ACE2 was assessed by Western-blot analysis, while the immune-localization of ACE2 was evaluated by immune-cytochemical analysis under confocal microscopy. Flow-cytometry experiments were also performed to assess the surface protein expression on a large number of cells. MAIN RESULTS AND THE ROLE OF CHANCE: The Western-blot analysis of sperm extracts demonstrated two specific bands, one of approximately 120 KDa, corresponding to the glycosylated full-length ACE2, and a second one of approximately 52 KDa, the molecular weight of the protein recently termed short-ACE2. The immune-cytochemical analysis showed a uniformly localization of full-length ACE2 along both the sperm head and the flagellum, whereas the short isoform was preferentially located in the post-acrosomal region of the sperm head and the midpiece. At the flow cytometer, semen samples displayed a wide between-subject variability both in the percentage of ACE2-positive spermatozoa and the density of protein surface expression. LIMITATIONS, REASONS FOR CAUTION: Further studies are needed to determine whether short-ACE2 is a cleavage product from the full-length protein or if it is originated during spermatogenesis. Moreover, the role and the interaction of ACE2 with SARS-CoV-2 in human spermatozoa should be clarified to evaluate the possible impact of the virus on sperm biology. WIDER IMPLICATIONS OF THE FINDINGS: Since mature spermatozoa are transcriptionally silent and SARS-CoV-2 is an RNA virus, it is unlikely that the virus could affect sperm biology by replicating itself. Nevertheless, the potential effects related to modifications of the sperm membrane or interaction with other receptors or specific proteins cannot be ruled out. TRIAL REGISTRATION NUMBER: not applicabl

26S PROTEASOME AND PKA MODULATE MAMMALIAN SPERM CAPACITATION BY CREATING AN INTEGRATED DIALOGUE: A COMPUTATIONAL ANALYSIS

Recent experimental evidence suggests the involvement of the 26S proteasome, the main protease active in eukaryotic cells, in the process that leads mammalian sperm to become fully fertile, so-called capacitation. Unfortunately, its role in male gametes signaling is still far from being completely understood. For this reason, here, we realized a computational model as an attempt to rebuild and explore 26S proteasome signaling cascade, aggregating all the molecular data available to date and realizing the Proteasome Interactome Network (PIN). Once obtained the network (i.e., a graph to represent the molecules as nodes and the interactions among them as links), we assessed its topology to infer important biological information. PIN is composed of 157 nodes, 248 links and it is characterized by a scale-free topology, following the Barabasi Albert model. In other words, it possesses a large amount of scarcely linked nodes and a small set of highly linked nodes, the hubs, which act as system controllers. This peculiar topology confers to the network relevant biological features: it is robust against random attacks, easily navigable and controllable and it is possible to infer new information from it. Indeed, the analysis of PIN showed that PKA and 26S proteasome were strongly interconnected and both were active in sperm signaling by influencing the protein phosphorylation pattern and then controlling several key events in sperm capacitation, such as membrane and cytoskeleton remodeling. In conclusion, the network model could explain many biological aspects of sperm physiology that are out of focus looking at the single molecular determinant, overcoming the reductionist approach which did not consider the complexity of molecules and their interactions. This could be helpful to identify potential diagnostic markers and therapeutic strategies concurring in explaining and approaching male infertility

Superconducting Transition and Vortex Pinning in Nb Films Patterned with Nano-scale Hole-arrays

Nb films containing extended arrays of holes with 45-nm diameter and 100-nm spacing have been fabricated using anodized aluminum oxide (AAO) as substrate. Pronounced matching effects in the magnetization and Little-Parks oscillations of the superconducting critical temperature have been observed in fields up to 9 kOe. Flux pinning in the patterned samples is enhanced by two orders of magnitude as compared to unpatterned reference samples in applied fields exceeding 5 kOe. Matching effects are a dominant contribution to vortex pinning at temperatures as low as 4.2 K due to the extremely small spacing of the holes

Inflammation gene variants and susceptibility to albuminuria in the U.S. population: analysis in the Third National Health and Nutrition Examination Survey (NHANES III), 1991-1994

<p>Abstract</p> <p>Background</p> <p>Albuminuria, a common marker of kidney damage, serves as an important predictive factor for the progression of kidney disease and for the development of cardiovascular disease. While the underlying etiology is unclear, chronic, low-grade inflammation is a suspected key factor. Genetic variants within genes involved in inflammatory processes may, therefore, contribute to the development of albuminuria.</p> <p>Methods</p> <p>We evaluated 60 polymorphisms within 27 inflammatory response genes in participants from the second phase (1991-1994) of the Third National Health and Nutrition Examination Survey (NHANES III), a population-based and nationally representative survey of the United States. Albuminuria was evaluated as logarithm-transformed albumin-to-creatinine ratio (ACR), as ACR ≥ 30 mg/g, and as ACR above sex-specific thresholds. Multivariable linear regression and haplotype trend analyses were conducted to test for genetic associations in 5321 participants aged 20 years or older. Differences in allele and genotype distributions among non-Hispanic whites, non-Hispanic blacks, and Mexican Americans were tested in additive and codominant genetic models.</p> <p>Results</p> <p>Variants in several genes were found to be marginally associated (uncorrected P value < 0.05) with log(ACR) in at least one race/ethnic group, but none remained significant in crude or fully-adjusted models when correcting for the false-discovery rate (FDR). In analyses of sex-specific albuminuria, <it>IL1B </it>(rs1143623) among Mexican Americans remained significantly associated with increased odds, while <it>IL1B </it>(rs1143623), <it>CRP </it>(rs1800947) and <it>NOS3 </it>(rs2070744) were significantly associated with ACR ≥ 30 mg/g in this population (additive models, FDR-P < 0.05). In contrast, no variants were found to be associated with albuminuria among non-Hispanic blacks after adjustment for multiple testing. The only variant among non-Hispanic whites significantly associated with any outcome was <it>TNF </it>rs1800750, which failed the test for Hardy-Weinberg proportions in this population. Haplotypes within <it>MBL2</it>, <it>CRP</it>, <it>ADRB2, IL4R</it>, <it>NOS3</it>, and <it>VDR </it>were significantly associated (FDR-P < 0.05) with log(ACR) or albuminuria in at least one race/ethnic group.</p> <p>Conclusions</p> <p>Our findings suggest a small role for genetic variation within inflammation-related genes to the susceptibility to albuminuria. Additional studies are needed to further assess whether genetic variation in these, and untested, inflammation genes alter the susceptibility to kidney damage.</p

Arboviral Etiologies of Acute Febrile Illnesses in Western South America, 2000–2007

Over recent decades, the variety and quantity of diseases caused by viruses transmitted to humans by mosquitoes and other arthropods (also known as arboviruses) have increased around the world. One difficulty in studying these diseases is the fact that the symptoms are often non-descript, with patients reporting such symptoms as low-grade fever and headache. Our goal in this study was to use laboratory tests to determine the causes of such non-descript illnesses in sites in four countries in South America, focusing on arboviruses. We established a surveillance network in 13 locations in Ecuador, Peru, Bolivia, and Paraguay, where patient samples were collected and then sent to a central laboratory for testing. Between May 2000 and December 2007, blood serum samples were collected from more than 20,000 participants with fever, and recent arbovirus infection was detected for nearly one third of them. The most common viruses were dengue viruses (genera Flavivirus). We also detected infection by viruses from other genera, including Alphavirus and Orthobunyavirus. This data is important for understanding how such viruses might emerge as significant human pathogens

Development of a novel protocol based on blood clot to improve the sensitivity of qPCR detection of toxoplasma gondii in peripheral blood specimens

Quantitative polymerase chain reaction (qPCR) for Toxoplasma gondii multicopy genes has emerged as a promising strategy for sensitive detection of parasite DNA. qPCR can be performed from blood samples, which are minimally invasive to collect. However, there is no consensus about what type of blood specimen yields the best sensitivity. The development of a novel protocol for qPCR detection of T. gondii using blood clot, involving an appropriate DNA extraction method and the use of an internal amplification control to monitor the reaction is presented in the current study. Assays directed to the B1 and REP529 genes were performed in spiked specimens of whole blood, guanidine–ethylenediaminetetraacetic acid blood, and clot. The clot-based qPCR was shown to be more sensitive when compared with other types of specimens, detecting five and 0.05 T. gondii genomes, using B1 and REP529 targets, respectively. Finally, a comparative analysis with samples from HIV patients with clinical suspicion of toxoplasmosis was performed, demonstrating the detection of four positive suspected cases with clots compared with only one using guanidine–ethylenediaminetetraacetic acid blood. The high analytical sensitivity and the cost-effective advantages offered by clot supports this methodology as a good laboratory tool to monitor parasite burden