Analysis of tissue transglutaminase function in the migration of swiss 3T3 fibroblasts - the active-state conformation of the enzyme does not affect cell motility but is important for its secretion

Increasing evidence suggests that tissue transglutaminase (tTGase; type II) is externalized from cells, where it may play a key role in cell attachment and spreading and in the stabilization of the extracellular matrix (ECM) through protein cross-linking. However, the relationship between these different functions and the enzyme’s mechanism of secretion is not fully understood. We have investigated the role of tTGase in cell migration using two stably transfected fibroblast cell lines in which expression of tTGase in its active and inactive (C277S mutant) states is inducible through the tetracycline-regulated system. Cells overexpressing both forms of tTGase showed increased cell attachment and decreased cell migration on fibronectin. Both forms of the enzyme could be detected on the cell surface, but only the clone overexpressing catalytically active tTGase deposited the enzyme into the ECM and cell growth medium. Cells overexpressing the inactive form of tTGase did not deposit the enzyme into the ECM or secrete it into the cell culture medium. Similar results were obtained when cells were transfected with tTGase mutated at Tyr274 (Y274A), the proposed site for the cis- ,trans peptide bond, suggesting that tTGase activity and/or its tertiary conformation dependent on this bond may be essential for its externalization mechanism. These results indicate that tTGase regulates cell motility as a novel cell-surface adhesion protein rather than as a matrix-cross-linking enzyme. They also provide further important insights into the mechanism of externalization of the enzyme into the extracellular matrix

Biocatalysis by transglutaminases: a review of biotechnological applications

The biocatalytic activity of transglutaminases (TGs) leads to the synthesis of new covalent isopeptide bonds (crosslinks) between peptide-bound glutamine and lysine residues, but also the transamidation of primary amines to glutamine residues, which ultimately can result into protein polymerisation. Operating with a cysteine/histidine/aspartic acid (Cys/His/Asp) catalytic triad, TGs induce the post-translational modification of proteins at both physiological and pathological conditions (e.g., accumulation of matrices in tissue fibrosis). Because of the disparate biotechnological applications, this large family of protein-remodelling enzymes have stimulated an escalation of interest. In the past 50 years, both mammalian and microbial TGs polymerising activity has been exploited in the food industry for the improvement of aliments’ quality, texture, and nutritive value, other than to enhance the food appearance and increased marketability. At the same time, the ability of TGs to crosslink extracellular matrix proteins, like collagen, as well as synthetic biopolymers, has led to multiple applications in biomedicine, such as the production of biocompatible scaffolds and hydrogels for tissue engineering and drug delivery, or DNA-protein bio-conjugation and antibody functionalisation. Here, we summarise the most recent advances in the field, focusing on the utilisation of TGs-mediated protein multimerisation in biotechnological and bioengineering applications

Utility of MYD88 in the Differential Diagnosis and Choice of Second-Line Therapy in a Case of Nonsecretory Lymphoplasmacytic Lymphoma versus Free Light Chain Waldenstrom’s Macroglobulinemia

The MYD88 L265P somatic variant (MYD88) has a high prevalence in Waldenstrom’s Macroglobulinemia (WM), a form of lymphoplasmacytic lymphoma (LPL) associated with monoclonal IgM. Although the role of MYD88 in WM was initially reported in 2012, it was not until 2016 that MYD88 testing was included in the National Cancer Care Network (NCCN) Guidelines. We present a case illustrating the utility of MYD88 status in distinguishing atypical forms of WM from marginal zone lymphoma (MZL) and in selecting second-line therapy with ibrutinib. In 2012, a 64-year-old male presented with dyspnea on exertion, a hemoglobin of 5.6 g/dL, a platelet count of 86,000, and monoclonal IgM kappa on serum immunofixation but no detectable M-spike. Bone marrow biopsy revealed 95% monoclonal B-lymphocytes with lymphoplasmacytic differentiation favoring a diagnosis of LPL/WM over MZL, with a favorable response to chemotherapy. This diagnosis was called into question 3 years later following relapse, and MZL was favored based on the lack of MYD88 mutation. One year later, however, repeat bone marrow biopsy detected the MYD88 mutation and therapy with ibrutinib yielded a favorable response. The distinction between certain lymphomas can be problematic and in this case MYD88 was helpful in clarifying a diagnosis of atypical LPL/WM from MZL and in selecting effective second-line therapy

The contributions of gender identification and gender ideologies to the purposes of social media use in adolescence

Gender differences in adolescent social media use are often documented in the research literature, yet few studies delve into why they occur. Accordingly, we investigated whether gender identification and gender ideologies are associated with five major purposes of social media use in adolescence (emotion and activity bonding with friends, social compensation, appearance validation, and bullying). Participants were 309 cisgender U.S. high school students (Mage = 15.74; 59% girls; 53% white) primarily using Instagram and Snapchat but also TikTok (more popular with girls) and Discord (more popular with boys) in 2019. Girls reported greater use of social media for emotion bonding, appearance validation, and social compensation compared to boys, who reported greater competitive activity bonding. Girls and boys did not differ in their use of social media for bullying. In linear regressions, masculinity ideology predicted purposes associated with girls (appearance validation, social compensation), as well as those associated with boys (competitive activity bonding), regardless of gender. Femininity ideology uniquely predicted emotion bonding and social compensation but only mediated the effect of gender for the latter. Findings illustrate that gender is important for understanding uses and gratifications of social media in adolescence, but traditional masculinity ideology is similar across genders and relates to multiple functions of social media in boys' and girls' lives. More work is needed to conceptualize gender beliefs and values in Gen Z, given recent challenges to gender binary ideology and low reliability of the scales in this study, which were developed before social media

Analysis of tissue transglutaminase function in the migration of swiss 3T3 fibroblasts - the active-state conformation of the enzyme does not affect cell motility but is important for its secretion

Increasing evidence suggests that tissue transglutaminase (tTGase; type II) is externalized from cells, where it may play a key role in cell attachment and spreading and in the stabilization of the extracellular matrix (ECM) through protein cross-linking. However, the relationship between these different functions and the enzyme’s mechanism of secretion is not fully understood. We have investigated the role of tTGase in cell migration using two stably transfected fibroblast cell lines in which expression of tTGase in its active and inactive (C277S mutant) states is inducible through the tetracycline-regulated system. Cells overexpressing both forms of tTGase showed increased cell attachment and decreased cell migration on fibronectin. Both forms of the enzyme could be detected on the cell surface, but only the clone overexpressing catalytically active tTGase deposited the enzyme into the ECM and cell growth medium. Cells overexpressing the inactive form of tTGase did not deposit the enzyme into the ECM or secrete it into the cell culture medium. Similar results were obtained when cells were transfected with tTGase mutated at Tyr274 (Y274A), the proposed site for the cis- ,trans peptide bond, suggesting that tTGase activity and/or its tertiary conformation dependent on this bond may be essential for its externalization mechanism. These results indicate that tTGase regulates cell motility as a novel cell-surface adhesion protein rather than as a matrix-cross-linking enzyme. They also provide further important insights into the mechanism of externalization of the enzyme into the extracellular matrix

Narratives of Gender, Sexuality, and Community in Three Generations of Genderqueer Sexual Minorities.

Genderqueer identities-those that challenge a strict binary between woman and man-are increasingly visible within mainstream culture and psychological research. However, little is known about generational differences in the lived experience of genderqueer people. Inductive thematic analysis of interviews with 30 genderqueer sexual minorities of 3 distinct generations living the United States revealed 3 major themes: (a) unintelligibility: genderqueer people face challenges in identifying, naming, and expressing their gender due to the constraints of everyday language and material culture; (b) managing stigma through challenging oppression: genderqueer people manage stigma by naming and challenging the gender binary, often in relation to other forms of oppression; and (c) connection beyond mainstream LGBTQ communities: genderqueer people often find connection outside of mainstream LGBTQ spaces, such as through ethnicity-based or sexual subcommunities (e.g., kink/BDSM, polyamorous). Within these themes, key generational patterns included (a) greater challenges among the middle and older generations in naming and expressing a genderqueer identity, especially in relation to their sexual identity; (b) intensified critique of mainstream LGBTQ politics among the younger generation; and (c) greater challenges in finding and maintaining community among the middle and older generations. Across generations, participants emphasized the need to create more inclusive environments by changing language and social structures to deemphasize the gender binary

Engagement with Master and Alternative Narratives of Gender and Sexuality Among LGBTQ+ Youth in the Digital Age

Gender and sexuality are contentious political issues in the US, with a resurgence of traditional master narratives for gender following decades of advances for gender equality. To understand how today’s LGBTQ+ youth navigate this narrative landscape in a polymedia context, we conducted social media tour interviews with 20 LGBTQ+ adolescents (aged 16–19), recording audiovisual data as they guided us through important posts on their top three public social media platforms. Through reflexive thematic analysis, we found that our participants were engaging with both longstanding master narratives (e.g., traditional gender roles) and contemporary alternative narratives (e.g., gender as non-binary) using three key navigational strategies for engaging with narratives on social media platforms: seeking and sharing information, creating queer community, and making choices about visibility and permanence. The meaning and purpose of these strategies for participants, both individually and collectively, could not be fully understood apart from three key navigational contexts: the traditional gender narrative, white liberal community context, and platform affordances. Our results demonstrate that narrative engagement for contemporary LGBTQ+ adolescents is deeply influenced by personal polymedia environments, identity intersections, and power structures shaping possibilities for individual identity expression and collective cultural transformation