Cross-platform gene expression signature of human spermatogenic failure reveals inflammatory-like response

BACKGROUND The molecular basis of human testicular dysfunction is largely unknown. Global gene expression profiling of testicular biopsies might reveal an expression signature of spermatogenic failure in azoospermic men. METHODS Sixty-nine individual testicular biopsy samples were analysed on two microarray platforms; selected genes were validated by quantitative real-time PCR and immunohistochemistry. RESULTS A minimum of 188 transcripts were significantly increased on both platforms. Their levels increased with the severity of spermatogenic damage and reached maximum levels in samples with Sertoli-cell-only appearance, pointing to genes expressed in somatic testicular cells. Over-represented functional annotation terms were steroid metabolism, innate defence and immune response, focal adhesion, antigen processing and presentation and mitogen-activated protein kinase K signalling pathway. For a considerable proportion of genes included in the expression signature, individual transcript levels were in keeping with the individual mast cell numbers of the biopsies. When tested on three disparate microarray data sets, the gene expression signature was able to clearly distinguish normal from defective spermatogenesis. More than 90% of biopsy samples clustered correctly into the corresponding category, emphasizing the robustness of our data. CONCLUSIONS A gene expression signature of human spermatogenic failure was revealed which comprised well-studied examples of inflammation-related genes also increased in other pathologies, including autoimmune disease

Recombinant Deg/HtrA proteases from Synechocystis sp. PCC 6803 differ in substrate specificity, biochemical characteristics and mechanism

Cyanobacteria require efficient protein-quality-control mechanisms to survive under dynamic, often stressful, environmental conditions. It was reported that three serine proteases, HtrA (high temperature requirement A), HhoA (HtrA homologue A) and HhoB (HtrA homologue B), are important for survival of Synechocystis sp. PCC 6803 under high light and temperature stresses and might have redundant physiological functions. In the present paper, we show that all three proteases can degrade unfolded model substrates, but differ with respect to cleavage sites, temperature and pH optima. For recombinant HhoA, and to a lesser extent for HtrA, we observed an interesting shift in the pH optimum from slightly acidic to alkaline in the presence of Mg2+ and Ca2+ ions. All three proteases formed different homo-oligomeric complexes with and without substrate, implying mechanistic differences in comparison with each other and with the well-studied Escherichia coli orthologues DegP (degradation of periplasmic proteins P) and DegS. Deletion of the PDZ domain decreased, but did not abolish, the proteolytic activity of all three proteases, and prevented substrate-induced formation of complexes higher than trimers by HtrA and HhoA. In summary, biochemical characterization of HtrA, HhoA and HhoB lays the foundation for a better understanding of their overlapping, but not completely redundant, stress-resistance functions in Synechocystis sp. PCC 6803

The role of discourse markers, backchannels and pauses on discourse structure in Alternative and Augmented Communication (AAC)

References: - Aijmer, K., & Simon-Vandenbergen, A. M. (2006). Pragmatic Markers in Contrast. Elsevier. - Fischer, K. (2006). Approaches to Discourse Particles. Elsevier. - Fraser, B. (1996). Pragmatic markers. Pragmatics. Quarterly Publication of the International Pragmatics Association (IPrA), 167–190. https://doi.org/10.1075/prag.6.2.03fra - Friginal, E., Pearson, P., Di Ferrante, L., Pickering, L., & Bruce, C. (2013). Linguistic characteristics of AAC discourse in the workplace. Discourse Studies, 15(3), 279–298. https://doi.org/10.1177/1461445613480586 - Weid-Goldschmidt, B. (2013). Zielgruppen Unterstützer Kommunikation. Looeper Verlag.Discourse markers and backchannels play an important role in connecting parts of as well as contributing to fluency in discourses (e.g. Fraser, 1996). While research on discourse markers on the verbal level in “typical” language use is abundant (e.g. Aijmer & Simon-Vandenbergen, 2006; Fischer, 2006), little is still known about the manifestation of discourse markers and backchannels in Augmentative and Alternative Communication (AAC) (see Friginal et al., 2013 for an exception). AAC discourses are “atypical” in that they are characterised by AAC users’ pauses for utterance production and overlaps with interlocutors’ turns using spoken language. To our knowledge, no multimodal approach has been taken so far to analyse the discourse of persons who communicate using AAC. To fill this gap, we address the question of how discourse markers, backchannels and pauses are employed multimodally in AAC. The data stems from six interviews with persons belonging to AAC groups 3 and 4 (cf. Weid-Goldschmidt, 2013) who communicate through speech-generating devices. Despite representing a close range in terms of AAC users, their communication shows a wide range of diversity and complexity. The interviews were carried out as part of an interdisciplinary project investigating the challenges experienced by AAC users during the transitions after compulsory school, entering higher education, a workplace, or an adult institution (Kollmar et al., 2018). Each interview lasted approximately two hours and was transcribed orthographically first. In each interview, key passages were selected where pragmatic stance-taking or discourse interventions on the part of the AAC users took place. These then underwent a detailed multimodal transcription in EXMARaLDA. Preliminary analyses of the data show that a wide variety of multimodal features characterize AAC discourse such as body movements, hand and head gestures, facial expressions, gaze, PORTA signs and conventionalized signs, vocalization and speech-generating devices being used alternately and sometimes simultaneously by AAC users to structure their discourse. Taking a close look at the structure of the discourse from a “typical” speaker’s normalized perspective on discourse, lengthened pauses can be perceived as atypical or fragmenting the discourse in AAC communication. For AAC users, characteristic features like pauses are essential for structuring their AAC discourse. Furthermore, with regard to the occurrence of discourse markers and particularly backchannels, it can be noted that there are several commonly used forms displayed to participate in the discourse, such as offering a turn to another person, the use of affirmation and negation signals and connectors which, depending on the circumstances, will be expressed through one or a combination of the above-mentioned multimodal features

Gemeinsam junge Menschen ermächtigen : wie Linguistik und Ergotherapie zusammenspannen

Was bedeutet UK beim Übergang ins Erwachsenenleben? Wie gehen junge Erwachsene, die UK als Ausdrucksmittel nutzen, um komplex zu kommunizieren, mit den Veränderungen um? Wie mit ihren sprachlichen Ressourcen? Forscherinnen der ZHAW untersuchen, was UK-Nutzer:innen nach der obligatorischen Schulzeit brauchen, und wollen mit diesen zusammen geeignete Hilfestellungen entwickeln. In zwei Inputreferaten berichten wir über die Ergebnisse. Anschliessend diskutieren wir, wie wir zusammenarbeiten können, um die in dem Lebensalter entstehende Versorgungslücke bestmöglich zu schliessen

Empowering young augmentative and alternative communication-users in their transition into adulthood

Individuals with difficulties producing speech often use augmentative and alternative communication (AAC) to interact with their social environment and to participate in society. A scoping review (Kollmar 2018) on the use and success of AAC showed a clear lack of research including adolescents and young adults. As individuals transition from a school setting into higher education, vocational training or into a workplace setting, communication needs change considerably. To successfully participate in life situations as adults, individuals using AAC require support in developing their language and communication skills during this phase in life. We aim to design appropriate measures to support AAC users in their transition into adulthood. In a first step, we are conducting a qualitative study to gain in-depth knowledge about their experiences and needs during this phase. In this ongoing project, we have so far completed 5 interviews with 2 men and 3 women (mean age 21.8 years, range 17-28 years). Interviewees are residents of the United States (1), Germany (1) or Switzerland (3). Two individuals are self-employed, one employed in the free labor market, one works in a sheltered workspace, and one is still a student. Qualitative content analysis revealed several important themes in the lived experiences of all interviewees. First, all interviewees reported having experienced a lack of appropriate support to reach their educational and professional goals from many individuals in their environment, including teachers, health professionals, and authorities. AAC users attributed that a lack of support to a lack of knowledge about AAC. In reaction, interviewees reported taking self-initiative, fighting for their rights, dreams and wishes and reaching their goals with support from family and friends. The knowledge gained in these interviews will be used to design targeted interventions to empower young AAC users in their transition into adulthood and entering the workforce. Reference: Kollmar, A., Hohenstein, C., Sabatino, A., & Gantschnig, B. (2018). Augmentative and Alternative Communication – Scoping Review / Unterstützte Kommunikation – Scoping Review. International Journal of Health Professions, 5(1), 91–108. https://doi.org/10.2478/ijhp-2018-0010 Funding Source: Swiss Federal Office for the Equality for Persons with Disabilitie

Differential marker protein expression specifies rarefaction zone-containing human Adark spermatogonia.

International audienceIt is unclear whether the distinct nuclear morphologies of human A(dark) (Ad) and A(pale) (Ap) spermatogonia are manifestations of different stages of germ cell development or phases of the mitotic cycle, or whether they may reflect still unknown molecular differences. According to the classical description by Clermont, human dark type A spermatogonium (Ad) may contain one, sometimes two or three nuclear 'vacuolar spaces' representing chromatin rarefaction zones. These structures were readily discerned in paraffin sections of human testis tissue during immunohistochemical and immunofluorescence analyses and thus represented robust morphological markers for our study. While a majority of the marker proteins tested did not discriminate between spermatogonia with and without chromatin rarefaction zones, doublesex- and mab-3-related transcription factor (DMRT1), tyrosine kinase receptor c-Kit/CD117 (KIT) and proliferation-associated antigen Ki-67 (KI-67) appeared to be restricted to subtypes which lacked the rarefaction zones. Conversely, exosome component 10 (EXOSC10) was found to accumulate within the rarefaction zones, which points to a possible role of this nuclear domain in RNA processing

Cross-platform gene expression signature of human spermatogenic failure reveals inflammatory-like response.

International audienceBACKGROUND: The molecular basis of human testicular dysfunction is largely unknown. Global gene expression profiling of testicular biopsies might reveal an expression signature of spermatogenic failure in azoospermic men. METHODS: Sixty-nine individual testicular biopsy samples were analysed on two microarray platforms; selected genes were validated by quantitative real-time PCR and immunohistochemistry. RESULTS: A minimum of 188 transcripts were significantly increased on both platforms. Their levels increased with the severity of spermatogenic damage and reached maximum levels in samples with Sertoli-cell-only appearance, pointing to genes expressed in somatic testicular cells. Over-represented functional annotation terms were steroid metabolism, innate defence and immune response, focal adhesion, antigen processing and presentation and mitogen-activated protein kinase K signalling pathway. For a considerable proportion of genes included in the expression signature, individual transcript levels were in keeping with the individual mast cell numbers of the biopsies. When tested on three disparate microarray data sets, the gene expression signature was able to clearly distinguish normal from defective spermatogenesis. More than 90% of biopsy samples clustered correctly into the corresponding category, emphasizing the robustness of our data. CONCLUSIONS: A gene expression signature of human spermatogenic failure was revealed which comprised well-studied examples of inflammation-related genes also increased in other pathologies, including autoimmune diseases

Screening for biomarkers of spermatogonia within the human testis: a whole genome approach.

International audienceBACKGROUND: A key step in studying the biology of spermatogonia is to determine their global gene expression profile. However, disassociation of these cells from the testis may alter their profile to a considerable degree. To characterize the molecular phenotype of human spermatogonia, including spermatogonial stem cells (SSCs), within their cognate microenvironment, a rare subtype of human defective spermatogenesis was exploited in which spermatogonia were the only germ cell type. METHODS: The global expression profile of these samples was assessed on the Affymetrix microarray platform and compared with tissues showing homogeneous Sertoli-cell-only appearance; selected genes were validated by quantitative real-time PCR and immunohistochemistry on disparate sample sets. RESULTS: Highly significant differences in gene expression levels correlated with the appearance of spermatogonia, including 239 best candidates of human spermatogonially expressed genes. Specifically, fibroblast growth factor receptor 3 (FGFR3), desmoglein 2 (DSG2), E3 ubiquitin ligase c-CBL (casitas B-cell lymphoma), cancer/testis antigen NY-ESO-1 (CTAG1A/B), undifferentiated embryonic cell transcription factor 1 (UTF1) and synaptosomal-associated protein, 91 kDa homolog (SNAP91) were shown to represent specific biomarkers of human spermatogonia. CONCLUSIONS: These biomarkers, specifically the surface markers FGFR3 and DSG2, may facilitate the isolation and enrichment of human stem and/or progenitor spermatogonia and thus lay a foundation for studies of long-term maintenance of human SSCs/progenitor cells, spermatogonial self-renewal, clonal expansion and differentiation