PyK2 and FAK connections to p190Rho guanine nucleotide exchange factor regulate RhoA activity, focal adhesion formation, and cell motility

Integrin binding to matrix proteins such as fibronectin (FN) leads to formation of focal adhesion (FA) cellular contact sites that regulate migration. RhoA GTPases facilitate FA formation, yet FA-associated RhoA-specific guanine nucleotide exchange factors (GEFs) remain unknown. Here, we show that proline-rich kinase-2 (Pyk2) levels increase upon loss of focal adhesion kinase (FAK) in mouse embryonic fibroblasts (MEFs). Additionally, we demonstrate that Pyk2 facilitates deregulated RhoA activation, elevated FA formation, and enhanced cell proliferation by promoting p190RhoGEF expression. In normal MEFs, p190RhoGEF knockdown inhibits FN-associated RhoA activation, FA formation, and cell migration. Knockdown of p190RhoGEF-related GEFH1 does not affect FA formation in FAK−/− or normal MEFs. p190RhoGEF overexpression enhances RhoA activation and FA formation in MEFs dependent on FAK binding and associated with p190RhoGEF FA recruitment and tyrosine phosphorylation. These studies elucidate a compensatory function for Pyk2 upon FAK loss and identify the FAK–p190RhoGEF complex as an important integrin-proximal regulator of FA formation during FN-stimulated cell motility

School and Bicultural Factors as Mediators between Immigrant Mothers’ Acculturative Stress and Adolescents’ Depression in Korea

In Korea, marriages between Korean men and foreign women have surged since the late 1990s, resulting in public interest in the psychosocial adjustment of their children. This study examined the mediating effects of immigrant mothers’ school involvement, adolescents’ school adjustment, and bicultural acceptance on the relationship between the mothers’ acculturative stress and adolescents’ depression, as well as whether the structural relationships differed by the sex of adolescents. Data were collected from 1238 dyads of first-grade students (605 boys, 633 girls; age = 12.97 ± 0.35 years) in Korean middle schools and their immigrant mothers (age = 43.52 ± 5.13 years) who participated in the Multicultural Adolescents Panel Study. The structural equation modeling analysis revealed that mothers’ acculturative stress was indirectly and positively related to adolescents’ depression through (1) the serial mediations of mothers’ school involvement and adolescents’ school adjustment and (2) the individual mediation of adolescents’ school adjustment. Furthermore, the multigroup analysis indicated that the relationships between adolescents’ school adjustment and depression and between adolescents’ bicultural acceptance and depression significantly differed between male and female adolescents. The study provides directions for schools and communities to increase immigrant mothers’ school involvement and to facilitate their children’s school adjustment and bicultural acceptance

Relationship between Marriage Immigrant Mothers’ Acculturative Stress and Their Adolescent Children’s Career Decidedness in South Korea: Mediating Roles of Parenting and School Adjustment

International marriages between Korean men and foreign women from other Asian countries have been increasing since the late 1990s in Korea. This study examines the mediating effects of parenting self-efficacy, career-specific parenting behaviors, and school adjustment on the relationship between immigrant mothers’ acculturative stress and their adolescent children’s career decidedness. Data were collected from 1181 third grade students (583 boys, 598 girls) in Korean middle schools and their foreign mothers who participated in the Multicultural Adolescents Panel Study. A structural equation modeling analysis revealed the following multiple mediation process: immigrant mothers’ acculturative stress is indirectly related to their adolescent children’s career decidedness through (1) the dual mediation of parenting self-efficacy and career-specific parenting behaviors; (2) the serial mediation of parenting self-efficacy, career-specific parenting behaviors, and adolescents’ school adjustment; (3) the dual mediation of parenting self-efficacy and adolescents’ school adjustment; and (4) the mediation of adolescents’ school adjustment. This study provides directions for parent education and career counseling to enhance immigrant mothers’ parenting competence and support the positive career development of adolescents from multicultural families. The study, therefore, helps them grow into well-adjusted adults in Korean society, which, in turn, contributes to the well-being of immigrant mothers and their adolescent children

Syndecan-4 regulates localization, activity and stability of protein kinase C-alpha.

During cell-matrix adhesion, syndecan-4 transmembrane heparan sulphate proteoglycan plays a critical role in the formation of focal adhesions and stress fibres. We have shown previously that the syndecan-4 cytoplasmic domain directly binds to and activates PKC-alpha (protein kinase C-alpha) in vitro [Oh, Woods and Couchman (1997) J. Biol. Chem. 272, 8133-8136]. However, whether syndecan-4 has the same activity in vivo needs to be addressed. Using mammalian two-hybrid assays, we showed that syndecan-4 interacted with PKC-alpha in vivo and that this interaction was mediated through syndecan-4 cytoplasmic domain. Furthermore, the activation of PKC increased the extent of interaction between syndecan-4 and PKC-alpha. Overexpression of syndecan-4, but not a mutant lacking its cytoplasmic domain, specifically increased the level of endogenous PKC-alpha and enhanced the translocation of PKC-alpha into both detergent-insoluble and membrane fractions. In addition, rat embryo fibroblasts overexpressing syndecan-4 exhibited a slowed down-regulation of PKC-alpha in response either to a prolonged treatment with PMA or to maintaining cells in suspension culture. PKC-alpha immunocomplex kinase assays also showed that syndecan-4 overexpression increased the activity of membrane PKC-alpha. Taken together, these results suggest that syndecan-4 interacts with PKC-alpha in vivo and regulates its localization, activity and stability

A Novel T Cell-Engaging Bispecific Antibody for Treating Mesothelin-Positive Solid Tumors

As mesothelin is overexpressed in various types of cancer, it is an attractive target for therapeutic antibodies. T-cell bispecific antibodies bind to target cells and engage T cells via binding to CD3, resulting in target cell killing by T-cell activation. However, the affinity of the CD3-binding arm may influence CD3-mediated plasma clearance or antibody trapping in T-cell-containing tissues. This may then affect the biodistribution of bispecific antibodies. In this study, we used scFab and knob-into-hole technologies to construct novel IgG-based 1 + 1 MG1122-A and 2 + 1 MG1122-B bispecific antibodies against mesothelin and CD3ε. MG1122-B was designed to be bivalent to mesothelin and monovalent to CD3ε, using a 2 + 1 head-to-tail format. Activities of the two antibodies were evaluated in mesothelin-positive tumor cells in vitro and xenograft models in vivo. Although both antibodies exhibited target cell killing efficacy and produced regression of xenograft tumors with CD8+ T-cell infiltration, the antitumor efficacy of MG1122-B was significantly higher. MG1122-B may improve tumor targeting because of its bivalency for tumor antigen. It may also reduce systemic toxicity by limiting the activation of circulating T cells. Thus, MG1122-B may be useful for treating mesothelin-positive solid tumors

Nuclear FAK promotes cell proliferation and survival through FERM-enhanced p53 degradation

FAK is known as an integrin- and growth factor-associated tyrosine kinase promoting cell motility. Here, we show that during mouse development, FAK inactivation results in p53- and p21-dependent mesodermal cell growth arrest. Reconstitution of primary FAK-/-p21-/-fibroblasts revealed that FAK, in a kinase-independent manner, facilitates p53 turnover via enhanced Mdm2-dependent p53 ubiquitination. p53 inactivation by FAK required FAK FERM F1 lobe binding to p53, FERM F2 lobe-mediated nuclear localization, and FERM F3 lobe for connections to Mdm2 and proteasomal degradation. Staurosporine or loss of cell adhesion enhanced FERM-dependent FAK nuclear accumulation. In primary human cells, FAK knockdown raised p53-p21 levels, slowed cell proliferation, but did not cause apoptosis. Notably, FAK knockdown plus cisplatin triggered p53-dependent cell apoptosis which was rescued by either full length FAK or FAK FERM re-expression. These studies define a scaffolding role for nuclear FAK in facilitating cell survival through enhanced p53 degradation under conditions of cellular stress

Automated Detection of Sleep Apnea-Hypopnea Events Based on 60 GHz Frequency-Modulated Continuous-Wave Radar Using Convolutional Recurrent Neural Networks: A Preliminary Report of a Prospective Cohort Study

Radar is a promising non-contact sensor for overnight polysomnography (PSG), the gold standard for diagnosing obstructive sleep apnea (OSA). This preliminary study aimed to demonstrate the feasibility of the automated detection of apnea-hypopnea events for OSA diagnosis based on 60 GHz frequency-modulated continuous-wave radar using convolutional recurrent neural networks. The dataset comprised 44 participants from an ongoing OSA cohort, recruited from July 2021 to April 2022, who underwent overnight PSG with a radar sensor. All PSG recordings, including sleep and wakefulness, were included in the dataset. Model development and evaluation were based on a five-fold cross-validation. The area under the receiver operating characteristic curve for the classification of 1-min segments ranged from 0.796 to 0.859. Depending on OSA severity, the sensitivities for apnea-hypopnea events were 49.0–67.6%, and the number of false-positive detections per participant was 23.4–52.8. The estimated apnea-hypopnea index showed strong correlations (Pearson correlation coefficient = 0.805–0.949) and good to excellent agreement (intraclass correlation coefficient = 0.776–0.929) with the ground truth. There was substantial agreement between the estimated and ground truth OSA severity (kappa statistics = 0.648–0.736). The results demonstrate the potential of radar as a standalone screening tool for OSA