Biology subjects

Billiar, K.

Publications and source records attributed to Billiar, K..

3 recordsLinked to original sources

bioRxiv2026

Virtual Immersion in Biomedical Engineering (VIBE): Exposing undergraduates to culturally sensitive engineering design and professional experiences at scale

ChallengeUndergraduate engineering students often face two major barriers: limited access to culturally sensitive global experiences and difficulty securing design internship opportunities. Traditional study abroad and internship programs can be inaccessible due to financial, geographic, or structural constraints, hindering the development of global competencies and practical engineering skills. Novel InitiativeTo address these gaps, we created the Virtual Immersion in Biomedical Engineering (VIBE) program, a free, inclusive, and scalable summer experience. The 8-week online program blends interactive sessions on the engineering design process (EDP), faculty led research talks, and professional development workshops. Collaborative team-based design challenges focused on global health and healthcare disparities are completed by international teams of 3-4 students. From 2021 to 2024, more than 800 students from over 20 countries participated, with an even balance of male and female students. Student presentations (four-minute videos uploaded to YouTube) were evaluated using rubrics with the aid of a large language model. The assessment revealed substantial learning of the EDP, especially in problem definition and communication. ReflectionParticipant feedback underscored the programs benefits: exposure to global collaboration, professional development, and flexibility. However, common challenges included time zone coordination and team dynamics. Despite these hurdles, VIBE has demonstrated that virtual experiential learning can effectively build engineering design skills and global awareness. It offers a promising, accessible alternative to traditional high-cost global programs, expanding equitable opportunities for engineering students worldwide.

bioengineering↗

bioRxiv2022

Multicellular Aligned Bands Disrupt Global Collective Cell Behavior

Mechanical stress patterns emerging from collective cell behavior have been shown to play critical roles in morphogenesis, tissue repair, and cancer metastasis. In our previous work utilizing microcontact printing to geometrically constrain valvular interstitial cell monolayers into specific shapes, we demonstrated that the general patterns of observed cell alignment, size, and apoptosis correlate with predicted mechanical stress fields if nonuniform cell properties are used in the computational models. However, these radially symmetric models did not predict the substantial heterogeneity in cell behavior observed in individual circular aggregates. The goal of this study is to determine how the heterogeneities in cell behavior emerge over time and diverge from the predicted collective cell behavior. Cell-cell interactions in circular multicellular aggregates of valvular interstitial cells were studied with time-lapse imaging ranging from hours to days, and migration, proliferation, and traction stresses were measured. Our results indicate that individual elongated cells create strong local alignment within pre-confluent cell populations on the microcontact printed protein islands. These cells influence the alignment of additional cells to create dense, locally aligned bands of cells which disrupt the global behavior. Cells are highly elongated at the endpoints of the bands yet have decreased spread area in the middle and reduced mobility. Although traction stresses at the endpoints of bands are enhanced, even to the point of detaching aggregates from the culture surface, the cells in dense bands exhibit reduced proliferation, less nuclear YAP, and increased apoptotic rates indicating a low stress environment. These findings suggest that strong local cell-cell interactions between primary fibroblastic cells can disrupt the global collective cellular behavior leading to substantial heterogeneity of cell behaviors in constrained monolayers. This local emergent behavior within aggregated fibroblasts may play an important role in development and disease of connective tissues.

bioengineering↗

bioRxiv2017

TRIP6 inhibits the Hippo signaling pathway in response to tension at adherens junctions

The transcriptional co-activator YAP controls cell proliferation, survival, and tissue regeneration in response to changes in the mechanical environment. It is not known how mechanical stimuli such as tension are sensed and how the signal is transduced to control YAP activity. Here we show that the LIM domain protein TRIP6 acts as part of a mechanotransduction pathway at adherens junctions to promote YAP activity by inhibiting the LATS1/2 kinases. Previous studies showed that vinculin at adherens junctions becomes activated by mechanical tension. We show that vinculin inhibits Hippo signaling by recruiting TRIP6 to adherens junctions and stimulating its binding to and inhibition of LATS1/2 in response to tension. TRIP6 competes with MOB1 for binding to LATS1/2 thereby blocking MOB1 from recruiting the LATS1/2 activating kinases MST1/2. Together these findings reveal a novel mechanotransduction cascade that transduces tension signals sensed at adherens junctions to control Hippo pathway signaling.

cell biology↗