Cellular mechanotransduction of human osteoblasts in microgravity.

Astronauts experience significant and rapid bone loss as a result of an extended stay in space, making the International Space Station (ISS) the perfect laboratory for studying osteoporosis due to the accelerated nature of bone loss on the ISS. This prompts the question, how does the lack of load due to zero-gravity propagate to bone-forming cells, human fetal osteoblasts (hFOBs), altering their maturation to mineralization? Here, we aim to study the mechanotransduction mechanisms by which bone loss occurs in microgravity. Two automated experiments, 4 microfluidic chips capable of measuring single-cell mechanics of hFOBs via aspiration and cell spheroids incubated in pressure-controlled chambers, were each integrated into a CubeLab deployed to the ISS National Laboratory. For the first experiment, we report protrusion measurements of aspirated cells after exposure to microgravity at the ISS and compare these results to ground control conducted inside the CubeLab. Our analysis revealed slightly elongated protrusions for space samples compared to ground samples indicating softening of hFOB cells in microgravity. In the second experiment, we encapsulated osteoblast spheroids in collagen gel and incubated the samples in pressure-controlled chambers. We found that microgravity significantly reduced filamentous actin levels in the hFOB spheroids. When subjected to pressure, the spheroids exhibited increased pSMAD1/5/9 expression, regardless of the microgravity condition. Moreover, microgravity reduced YAP expression, while pressure increased YAP levels, thus restoring YAP expression for spheroids in microgravity. Our study provides insights into the influence of microgravity on the mechanical properties of bone cells and the impact of compressive pressure on cell behavior and signaling in space.

Cellular mechanotransduction of human osteoblasts in microgravity.

Astronauts experience significant and rapid bone loss as a result of an extended stay in space, making the International Space Station (ISS) the perfect laboratory for studying osteoporosis due to the accelerated nature of bone loss on the ISS. This prompts the question, how does the lack of load due to zero-gravity propagate to bone-forming cells, human fetal osteoblasts (hFOBs), altering their maturation to mineralization? Here, we aim to study the mechanotransduction mechanisms by which bone loss occurs in microgravity. Two automated experiments, microfluidic chips capable of measuring single-cell mechanics via aspiration and cell spheroids incubated in pressure-controlled chambers, were each integrated into a CubeLab deployed to the ISS National Laboratory. For the first experiment, we report protrusion measurements of aspirated cells after exposure to microgravity at the ISS and compare these results to ground control conducted inside the CubeLab. We found slightly elongated protrusions for space samples compared to ground samples indicating softening of hFOB cells in microgravity. In the second experiment, we encapsulated osteoblast spheroids in collagen gel and incubated the samples in pressure-controlled chambers. We found that microgravity significantly reduced filamentous actin levels in the hFOB spheroids. When subjected to pressure, the spheroids exhibited increased pSMAD1/5/9 expression, regardless of the microgravity condition. Moreover, microgravity reduced YAP expression, while pressure increased YAP levels, thus restoring YAP expression for spheroids in microgravity. Our study provides insights into the influence of microgravity on the mechanical properties of bone cells and the impact of compressive pressure on cell signaling in space.

Matrix confinement modulates 3D spheroid sorting and burst-like collective migration.

While it is known that cells with differential adhesion tend to segregate and preferentially sort, the physical forces governing sorting and invasion in heterogeneous tumors remain poorly understood. To investigate this, we tune matrix confinement, mimicking changes in the stiffness and confinement of the tumor microenvironment, to explore how physical confinement influences individual and collective cell migration in 3D spheroids. High levels of confinement lead to cell sorting while reducing matrix confinement triggers the collective fluidization of cell motion. Cell sorting, which depends on cell-cell adhesion, is crucial to this phenomenon. Burst-like migration does not occur for spheroids that have not undergone sorting, regardless of the degree of matrix confinement. Using computational Self-Propelled Voronoi modeling, we show that spheroid sorting and invasion into the matrix depend on the balance between cell-generated forces and matrix resistance. The findings support a model where matrix confinement modulates 3D spheroid sorting and unjamming in an adhesion-dependent manner, providing insights into the mechanisms of cell sorting and migration in the primary tumor and toward distant metastatic sites. STATEMENT OF SIGNIFICANCE: The mechanical properties of the tumor microenvironment significantly influence cancer cell migration within the primary tumor, yet how these properties affect intercellular interactions in heterogeneous tumors is not well understood. By utilizing calcium and calcium chelators, we dynamically alter collagen-alginate hydrogel stiffness and investigate tumor cell behavior within co-culture spheroids in response to varying degrees of matrix confinement. High confinement is found to trigger cell sorting while reducing confinement for sorted spheroids facilitates collective cell invasion. Notably, without prior sorting, spheroids do not exhibit burst-like migration, regardless of confinement levels. This work establishes that matrix confinement and intercellular adhesion regulate 3D spheroid dynamics, offering insights into cellular organization and migration within the primary tumor.

Matrix confinement modulates 3D spheroid sorting and burst-like collective migration.

While it is known that cells with differential adhesion tend to segregate and preferentially sort, the physical forces governing sorting and invasion in heterogeneous tumors remain poorly understood. To investigate this, we tune matrix confinement, mimicking changes in the stiffness and confinement of the tumor microenvironment, to explore how physical confinement influences individual and collective cell migration in 3D spheroids. High levels of confinement lead to cell sorting while reducing matrix confinement triggers the collective fluidization of cell motion. Cell sorting, which depends on cell-cell adhesion, is crucial to this phenomenon. Burst-like migration does not occur for spheroids that have not undergone sorting, regardless of the degree of matrix confinement. Using computational Self-Propelled Voronoi modeling, we show that spheroid sorting and invasion into the matrix depend on the balance between cell-generated forces and matrix resistance. The findings support a model where matrix confinement modulates 3D spheroid sorting and unjamming in an adhesion-dependent manner, providing insights into the mechanisms of cell sorting and migration in the primary tumor and toward distant metastatic sites.

When Shepherds Shed: Trajectories of Weight-Related Behaviors in a Holistic Health Intervention Tailored for US Christian Clergy.

Maintaining healthy behaviors is challenging. Based upon previous reports that in North Carolina (NC), USA, overweight/obese clergy lost weight during a two-year religiously tailored health intervention, we described trajectories of diet, physical activity, and sleep. We investigated whether behavior changes were associated with weight and use of health-promoting theological messages. Improvements were observed in sleep, calorie-dense food intake, and physical activity, with the latter two associated with weight loss. While theological messages were well-retained, their relationship with behaviors depended on the specific message, behavior, and timing. Findings offer insights into weight loss mechanisms, including the role of theological messages in religiously tailored health interventions.

Personal and family perfectionism among Asian and Latinx youth.

OBJECTIVES: The goals of the study were to examine the number and types of personal and family perfectionists in a sample of Asian and Latinx youth and to explore group differences between the perfectionistic groups on youth functioning and self-compassion. METHOD: A total of 707 Asian American and 371 Latinx American youth (Mage = 14.10, SD = .59; 51.8% male and 48.0% female) completed self-report measures of personal and family perfectionism, self-compassion and self-coldness, and youth functioning. RESULTS: Cluster analysis revealed three types of personal perfectionists and three types of perfectionistic families (adaptive perfectionistic, maladaptive perfectionistic, and nonperfectionistic individuals and families). Adaptive personal and family perfectionists reported highest levels of self-compassion, and lowest levels of self-coldness, and internalizing and externalizing behaviors. There were significant interaction effects between personal and family perfectionists. Adaptive perfectionists who came from adaptive perfectionistic families reported significantly lower levels of self-coldness, internalizing and externalizing behaviors. Finally, individuals who reported high levels of discrepancy and also came from maladaptive perfectionistic families exhibited highest levels of distress. CONCLUSIONS: Our study revealed the importance of taking into account both the roles of personal and family perfectionism when working with youth of Asian and Latinx descent. In particular, perceived high expectations from families may exacerbate the detrimental effects associated with youth setting high standards for themselves. In contrast, family's healthy expectations and responses toward failure can buffer against the negative effects of youth's own maladaptive perfectionistic tendencies. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Compressive stress drives adhesion-dependent unjamming transitions in breast cancer cell migration.

Cellular unjamming is the collective fluidization of cell motion and has been linked to many biological processes, including development, wound repair, and tumor growth. In tumor growth, the uncontrolled proliferation of cancer cells in a confined space generates mechanical compressive stress. However, because multiple cellular and molecular mechanisms may be operating simultaneously, the role of compressive stress in unjamming transitions during cancer progression remains unknown. Here, we investigate which mechanism dominates in a dense, mechanically stressed monolayer. We find that long-term mechanical compression triggers cell arrest in benign epithelial cells and enhances cancer cell migration in transitions correlated with cell shape, leading us to examine the contributions of cell-cell adhesion and substrate traction in unjamming transitions. We show that cadherin-mediated cell-cell adhesion regulates differential cellular responses to compressive stress and is an important driver of unjamming in stressed monolayers. Importantly, compressive stress does not induce the epithelial-mesenchymal transition in unjammed cells. Furthermore, traction force microscopy reveals the attenuation of traction stresses in compressed cells within the bulk monolayer regardless of cell type and motility. As traction within the bulk monolayer decreases with compressive pressure, cancer cells at the leading edge of the cell layer exhibit sustained traction under compression. Together, strengthened intercellular adhesion and attenuation of traction forces within the bulk cell sheet under compression lead to fluidization of the cell layer and may impact collective cell motion in tumor development and breast cancer progression.

Compression enhances invasive phenotype and matrix degradation of breast Cancer cells via Piezo1 activation.

BACKGROUND: Uncontrolled growth in solid breast cancer generates mechanical compression that may drive the cancer cells into a more invasive phenotype, but little is known about how such compression affects the key events and corresponding regulatory mechanisms associated with invasion of breast cancer cells including cellular behaviors and matrix degradation. RESULTS: Here we show that compression enhanced invasion and matrix degradation of breast cancer cells. We also identified Piezo1 as the putative mechanosensitive cellular component that transmitted compression to not only enhance the invasive phenotype, but also induce calcium influx and downstream Src signaling. Furthermore, we demonstrated that Piezo1 was mainly localized in caveolae, and both Piezo1 expression and compression-enhanced invasive phenotype of the breast cancer cells were reduced when caveolar integrity was compromised by either knocking down caveolin1 expression or depleting cholesterol content. CONCLUSIONS: Taken together, our data indicate that mechanical compression activates Piezo1 channels to mediate enhanced breast cancer cell invasion, which involves both cellular events and matrix degradation. This may be a critical mechanotransduction pathway during breast cancer metastasis, and thus potentially a novel therapeutic target for the disease.

Assessing Health Needs in African American Churches: A Mixed-Methods Study.

Among major racial and ethnic groups in the USA, African Americans are the most religious, and faith-based organizations play an important role in health promotion for African Americans. This study aimed to assess health needs in African American churches using a mixed-methods approach. Based on quantitative and qualitative data collected from eight African American churches in Nebraska in 2017, the most prevalent chronic conditions among participating African American church members (n = 388) included hypertension (60.8%), allergies (41.0%), arthritis (36.4%), high cholesterol (35.8%), and diabetes (28.1%). Significant predictors of fair or poor health were identified as male sex, unemployment, delayed utilization of health care in the past 12 months due to cost, lower frequency of church attendance, and feeling down, depressed, or hopeless in the past 2 weeks. Pastors from participating churches identified cost as one of the primary barriers to providing church-based health services. There were substantial unmet health needs in African American faith communities, especially in the areas of chronic disease prevention and management, and churches would need more support to realize their full potential in faith-based health promotion.

Healthcare provider perspectives regarding epilepsy care in Uganda.

OBJECTIVE: Epilepsy is the most common chronic neurological disorder in the world and imposes a large economic burden on global healthcare systems, especially in low-income settings and rural areas as is found in sub-Saharan Africa (SSA). Despite the high epilepsy prevalence, there are no systematic descriptions of healthcare provider (HCP) perceptions and needs in managing people with epilepsy (PWE) in Uganda. Identifying these perceptions and needs is crucial for understanding community priorities, thereby enhancing the development of culturally sensitive communications, interventions, and research approaches. METHODS: In this qualitative study, we used semistructured interview guides to conduct focus group discussions that explored the perspectives of 32 providers of epilepsy care from health facilities around Mbarara, Uganda. Our sample included nonspecialized general physicians (n = 3), medical residents (n = 8), medical clinical officers (n = 3), psychiatric clinical nurses (n = 6), medical nurses and nursing assistants (n = 9), and other providers (n = 3), who were loosely grouped into discussion groups based on level or type of training. Self-assessed proficiency ratings were also administered to gain a better understanding of participants' confidence in their training, preparedness, and capabilities regarding epilepsy care. Thematic analysis of the focus group transcripts was conducted to ascertain commonly occurring themes about perceptions and challenges in epilepsy care. RESULTS: Our analyses identified nine major themes that dominated the perspectives of the study participants: care management, medications, diagnostics, HCP training, human resources, location, patient education, social support, and community knowledge and beliefs. Proficiency ratings prioritized areas of confidence as knowledge related to referrals, psychosocial impacts, and seizure neurophysiology. Areas of need were revealed as knowledge of diagnostic tools and antiepileptic drug (AED) regimens. CONCLUSIONS: Our findings delineate the perspectives of providers caring for PWE, with consistent recognition of challenges centering around resource augmentation, infrastructure strengthening, and education. Participants emphasized the urgent need to augment these resources to address limitations in medication types and access, trained human resources, and diagnostic tools. They overwhelmingly recognized the need for infrastructure strengthening to address human, diagnostic, medicinal, and capital resource limitations that place undue burden on patients with epilepsy and physicians. Providers indicated a clear desire to learn more about different diagnostic tools and medical management practices, potentially through continuing education, specialized training, or more intentional in-school diagnostic preparation. They also advocated for the powerful influence of patient and family education and clearly articulated the need for community sensitization and support. This article is part of the Special Issue "The Intersection of Culture, Resources, and Disease: Epilepsy Care in Uganda".

Using a holistic health approach to achieve weight-loss maintenance: results from the Spirited Life intervention.

Weight-loss maintenance is essential to sustain the health benefits of weight loss. Studies with lower intensity intervention supports under real-world conditions are lacking. This study examined changes in weight and cardiometabolic biomarkers among Spirited Life participants following initial 12-month weight loss at 12-24 months and 24-42 months. A total of 719 clergy received a wellness intervention, including a 10-week online weight-loss program in the first 12 months and monthly health coaching throughout 24 months. Mean changes in weight, blood pressure, high-density lipoproteins, and triglycerides were estimated using random effects linear models, accounting for repeated measures. Weight was additionally analyzed in subsamples stratified by body mass index (BMI). At baseline, 17.1% of participants had BMI < 25 kg/m2 and 11.8% had BMI ≥ 40 kg/m2. Mean 12-month weight loss was -2.4 kg (95% CI: -2.8 kg, -2.1 kg). On average, at 42 months, participants regained weight but did not exceed baseline (-0.5 kg, 95% CI: -1.2 kg, 0.2 kg), improvements in triglycerides were completely sustained (-13.9 mg/dL, 95% CI: -18.6 mg/dL, -9.2 mg/dL), and systolic blood pressure improvements remained significant (-1.9 mmHg, 95% CI: -3.0 mmHg, -0.9 mmHg). Participants with a BMI ≥ 40 kg/m2 lost significantly more weight that was sustained at 42 months (-5.8 kg, 95% CI: -8.9 kg, -2.7 kg). The Spirited Life wellness intervention produced weight loss and, for participants with higher levels of obesity, sustained weight-loss maintenance. The intervention was effective for long-term prevention of weight gain among participants with BMI of 25 to ≤40 kg/m2, through 42 months. Wellness interventions such as Spirited Life should be considered for adoption.